fix: mobile adjustments

update: add data-storage warnings to the app

Cargo.lock

@@ -43,6 +43,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "approx"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cab112f0a86d568ea0e627cc1d6be74a1e9cd55214684db5561995f6dad897c6"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
@@ -414,7 +423,7 @@ dependencies = [
 
 [[package]]
 name = "ironcalc"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "chrono",
@@ -430,7 +439,7 @@ dependencies = [
 
 [[package]]
 name = "ironcalc_base"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "chrono",
@@ -443,11 +452,12 @@ dependencies = [
  "ryu",
  "serde",
  "serde_json",
+ "statrs",
 ]
 
 [[package]]
 name = "ironcalc_nodejs"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc",
  "napi",
@@ -782,7 +792,7 @@ dependencies = [
 
 [[package]]
 name = "pyroncalc"
-version = "0.5.7"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "ironcalc",
@@ -965,6 +975,16 @@ version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "38b58827f4464d87d377d175e90bf58eb00fd8716ff0a62f80356b5e61555d0d"
 
+[[package]]
+name = "statrs"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a3fe7c28c6512e766b0874335db33c94ad7b8f9054228ae1c2abd47ce7d335e"
+dependencies = [
+ "approx",
+ "num-traits",
+]
+
 [[package]]
 name = "subtle"
 version = "2.5.0"
@@ -1075,7 +1095,7 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc_base",
  "serde",

Dockerfile

@@ -0,0 +1,93 @@
+FROM rust:latest AS builder
+
+WORKDIR /app
+COPY . .
+
+# Tools + wasm toolchain + Node via nvm
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      bash curl ca-certificates make \
+    && rustup target add wasm32-unknown-unknown \
+    && cargo install wasm-pack \
+    && bash -lc "curl -fsSL https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash -" \
+    && bash -lc '\
+         export NVM_DIR="$HOME/.nvm" && \
+         source "$NVM_DIR/nvm.sh" && \
+         nvm install 22 && nvm alias default 22 && \
+         nroot="$NVM_DIR/versions/node/$(nvm version default)/bin" && \
+         ln -sf "$nroot/node" /usr/local/bin/node && \
+         ln -sf "$nroot/npm"  /usr/local/bin/npm  && \
+         ln -sf "$nroot/npx"  /usr/local/bin/npx \
+       ' \
+    && npm install typescript \
+    && rm -rf /var/lib/apt/lists/*
+
+# build the server
+RUN cargo build --release --manifest-path webapp/app.ironcalc.com/server/Cargo.toml
+
+# build the wasm
+RUN make -C bindings/wasm
+
+# build the widget
+WORKDIR /app/webapp/IronCalc
+RUN npm install && npm run build
+
+# build the frontend app
+WORKDIR /app/webapp/app.ironcalc.com/frontend
+RUN npm install && npm run build
+
+# build the xlsx_2_icalc binary (we don't need the release version here)
+WORKDIR /app/xlsx
+RUN cargo build
+
+WORKDIR /app
+# copy the artifacts to a dist/ directory
+RUN mkdir dist
+RUN mkdir dist/frontend
+RUN cp -r webapp/app.ironcalc.com/frontend/dist/* dist/frontend/
+RUN mkdir dist/server
+RUN cp webapp/app.ironcalc.com/server/target/release/ironcalc_server dist/server/
+RUN cp webapp/app.ironcalc.com/server/Rocket.toml dist/server/
+RUN cp webapp/app.ironcalc.com/server/ironcalc.sqlite dist/server/
+
+# Create ic files in docs
+RUN mkdir -p dist/frontend/models
+
+# Loop over all xlsx files in xlsx/tests/docs & templates and convert them to .ic
+RUN bash -lc 'set -euo pipefail; \
+  mkdir -p dist/frontend/models; \
+  shopt -s nullglob; \
+  for xlsx_file in xlsx/tests/docs/*.xlsx; do \
+    base_name="${xlsx_file##*/}"; base_name="${base_name%.xlsx}"; \
+    ./target/debug/xlsx_2_icalc "$xlsx_file" "dist/frontend/models/${base_name}.ic"; \
+  done; \
+  for xlsx_file in xlsx/tests/templates/*.xlsx; do \
+    base_name="${xlsx_file##*/}"; base_name="${base_name%.xlsx}"; \
+    ./target/debug/xlsx_2_icalc "$xlsx_file" "dist/frontend/models/${base_name}.ic"; \
+  done'
+
+# ---------- server runtime ----------
+FROM debian:bookworm-slim AS server-runtime
+RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates && \
+    rm -rf /var/lib/apt/lists/*
+WORKDIR /app
+# Copy EVERYTHING you put in dist/server (binary + Rocket.toml + DB)
+COPY --from=builder /app/dist/server/ ./
+# Make sure Rocket binds to the container IP; explicitly point to the config file
+ENV ROCKET_ADDRESS=0.0.0.0 \
+    ROCKET_PORT=8000 \
+    ROCKET_CONFIG=/app/Rocket.toml
+EXPOSE 8000
+# Run from /app so relative paths in Rocket.toml/DB work
+CMD ["./ironcalc_server"]
+
+# ---------- caddy runtime (serves frontend + reverse-proxy /api) ----------
+FROM caddy:latest AS caddy-runtime
+
+WORKDIR /srv
+
+# Copy the frontend build output to /srv
+COPY --from=builder /app/dist/frontend/ /srv/
+
+# Copy the Caddyfile
+COPY --from=builder /app/webapp/app.ironcalc.com/Caddyfile.compose /etc/caddy/Caddyfile
+

README.md

@@ -31,7 +31,17 @@ This repository contains the main engine and the xlsx reader and writer.
 
 Programmed in Rust, you will be able to use it from a variety of programming languages like Python, JavaScript (wasm), nodejs and possibly R, Julia or Go.
 
-We will build different _skins_: in the terminal, as a desktop application or use it in you own web application.
+We will build different _skins_: in the terminal, as a desktop application or use it in your own web application.
+
+# Docker
+
+If you have docker installed just run:
+
+```bash
+docker compose up --build
+```
+
+head over to <http://localhost:2080> to test the application.
 
 # Building
 
@@ -84,7 +94,7 @@ And then use this code in `main.rs`:
 
 ```rust
 use ironcalc::{
-    base::{expressions::utils::number_to_column, model::Model},
+    base::{expressions::utils::number_to_column, Model},
     export::save_to_xlsx,
 };
 

base/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ironcalc_base"
-version = "0.5.0"
+version = "0.6.0"
 authors = ["Nicolás Hatcher <nicolas@theuniverse.today>"]
 edition = "2021"
 homepage = "https://www.ironcalc.com"
@@ -19,6 +19,7 @@ regex = { version = "1.0", optional = true}
 regex-lite = { version = "0.1.6", optional = true}
 bitcode = "0.6.3"
 csv = "1.3.0"
+statrs = { version = "0.18.0", default-features = false, features = [] }
 
 [features]
 default = ["use_regex_full"]

base/src/cast.rs

@@ -5,6 +5,7 @@ use crate::{
         token::Error,
         types::CellReferenceIndex,
     },
+    formatter::format::parse_formatted_number,
     model::Model,
 };
 
@@ -14,6 +15,23 @@ pub(crate) enum NumberOrArray {
 }
 
 impl Model {
+    pub(crate) fn cast_number(&self, s: &str) -> Option<f64> {
+        match s.trim().parse::<f64>() {
+            Ok(f) => Some(f),
+            _ => {
+                let currency = &self.locale.currency.symbol;
+                let mut currencies = vec!["$", "€"];
+                if !currencies.iter().any(|e| *e == currency) {
+                    currencies.push(currency);
+                }
+                // Try to parse as a formatted number (e.g., dates, currencies, percentages)
+                if let Ok((v, _number_format)) = parse_formatted_number(s, &currencies) {
+                    return Some(v);
+                }
+                None
+            }
+        }
+    }
     pub(crate) fn get_number_or_array(
         &mut self,
         node: &Node,
@@ -21,9 +39,9 @@ impl Model {
     ) -> Result<NumberOrArray, CalcResult> {
         match self.evaluate_node_in_context(node, cell) {
             CalcResult::Number(f) => Ok(NumberOrArray::Number(f)),
-            CalcResult::String(s) => match s.parse::<f64>() {
-                Ok(f) => Ok(NumberOrArray::Number(f)),
-                _ => Err(CalcResult::new_error(
+            CalcResult::String(s) => match self.cast_number(&s) {
+                Some(f) => Ok(NumberOrArray::Number(f)),
+                None => Err(CalcResult::new_error(
                     Error::VALUE,
                     cell,
                     "Expecting number".to_string(),
@@ -89,16 +107,16 @@ impl Model {
         self.cast_to_number(result, cell)
     }
 
-    fn cast_to_number(
+    pub(crate) fn cast_to_number(
         &mut self,
         result: CalcResult,
         cell: CellReferenceIndex,
     ) -> Result<f64, CalcResult> {
         match result {
             CalcResult::Number(f) => Ok(f),
-            CalcResult::String(s) => match s.parse::<f64>() {
-                Ok(f) => Ok(f),
-                _ => Err(CalcResult::new_error(
+            CalcResult::String(s) => match self.cast_number(&s) {
+                Some(f) => Ok(f),
+                None => Err(CalcResult::new_error(
                     Error::VALUE,
                     cell,
                     "Expecting number".to_string(),

base/src/expressions/parser/static_analysis.rs

@@ -341,7 +341,8 @@ fn static_analysis_offset(args: &[Node]) -> StaticResult {
         }
         _ => return StaticResult::Unknown,
     };
-    StaticResult::Unknown
+    // Both height and width are explicitly 1, so OFFSET will return a single cell
+    StaticResult::Scalar
 }
 
 // fn static_analysis_choose(_args: &[Node]) -> StaticResult {
@@ -575,6 +576,37 @@ fn args_signature_xnpv(arg_count: usize) -> Vec<Signature> {
     }
 }
 
+// NETWORKDAYS(start_date, end_date, [holidays])
+// Parameters: start_date (scalar), end_date (scalar), holidays (optional vector)
+fn args_signature_networkdays(arg_count: usize) -> Vec<Signature> {
+    if arg_count == 2 {
+        vec![Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 3 {
+        vec![Signature::Scalar, Signature::Scalar, Signature::Vector]
+    } else {
+        vec![Signature::Error; arg_count]
+    }
+}
+
+// NETWORKDAYS.INTL(start_date, end_date, [weekend], [holidays])
+// Parameters: start_date (scalar), end_date (scalar), weekend (optional scalar), holidays (optional vector)
+fn args_signature_networkdays_intl(arg_count: usize) -> Vec<Signature> {
+    if arg_count == 2 {
+        vec![Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 3 {
+        vec![Signature::Scalar, Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 4 {
+        vec![
+            Signature::Scalar,
+            Signature::Scalar,
+            Signature::Scalar,
+            Signature::Vector,
+        ]
+    } else {
+        vec![Signature::Error; arg_count]
+    }
+}
+
 // FIXME: This is terrible duplications of efforts. We use the signature in at least three different places:
 // 1. When computing the function
 // 2. Checking the arguments to see if we need to insert the implicit intersection operator
@@ -690,13 +722,28 @@ fn get_function_args_signature(kind: &Function, arg_count: usize) -> Vec<Signatu
         Function::Maxifs => vec![Signature::Vector; arg_count],
         Function::Minifs => vec![Signature::Vector; arg_count],
         Function::Date => args_signature_scalars(arg_count, 3, 0),
+        Function::Datedif => args_signature_scalars(arg_count, 3, 0),
+        Function::Datevalue => args_signature_scalars(arg_count, 1, 0),
         Function::Day => args_signature_scalars(arg_count, 1, 0),
         Function::Edate => args_signature_scalars(arg_count, 2, 0),
         Function::Eomonth => args_signature_scalars(arg_count, 2, 0),
         Function::Month => args_signature_scalars(arg_count, 1, 0),
+        Function::Time => args_signature_scalars(arg_count, 3, 0),
+        Function::Timevalue => args_signature_scalars(arg_count, 1, 0),
+        Function::Hour => args_signature_scalars(arg_count, 1, 0),
+        Function::Minute => args_signature_scalars(arg_count, 1, 0),
+        Function::Second => args_signature_scalars(arg_count, 1, 0),
         Function::Now => args_signature_no_args(arg_count),
         Function::Today => args_signature_no_args(arg_count),
         Function::Year => args_signature_scalars(arg_count, 1, 0),
+        Function::Days => args_signature_scalars(arg_count, 2, 0),
+        Function::Days360 => args_signature_scalars(arg_count, 2, 1),
+        Function::Weekday => args_signature_scalars(arg_count, 1, 1),
+        Function::Weeknum => args_signature_scalars(arg_count, 1, 1),
+        Function::Workday => args_signature_scalars(arg_count, 2, 1),
+        Function::WorkdayIntl => args_signature_scalars(arg_count, 2, 2),
+        Function::Yearfrac => args_signature_scalars(arg_count, 2, 1),
+        Function::Isoweeknum => args_signature_scalars(arg_count, 1, 0),
         Function::Cumipmt => args_signature_scalars(arg_count, 6, 0),
         Function::Cumprinc => args_signature_scalars(arg_count, 6, 0),
         Function::Db => args_signature_scalars(arg_count, 4, 1),
@@ -785,6 +832,63 @@ fn get_function_args_signature(kind: &Function, arg_count: usize) -> Vec<Signatu
         Function::Formulatext => args_signature_scalars(arg_count, 1, 0),
         Function::Unicode => args_signature_scalars(arg_count, 1, 0),
         Function::Geomean => vec![Signature::Vector; arg_count],
+        Function::Networkdays => args_signature_networkdays(arg_count),
+        Function::NetworkdaysIntl => args_signature_networkdays_intl(arg_count),
+        Function::Acot => args_signature_scalars(arg_count, 1, 0),
+        Function::Acoth => args_signature_scalars(arg_count, 1, 0),
+        Function::Cot => args_signature_scalars(arg_count, 1, 0),
+        Function::Coth => args_signature_scalars(arg_count, 1, 0),
+        Function::Csc => args_signature_scalars(arg_count, 1, 0),
+        Function::Csch => args_signature_scalars(arg_count, 1, 0),
+        Function::Sec => args_signature_scalars(arg_count, 1, 0),
+        Function::Sech => args_signature_scalars(arg_count, 1, 0),
+        Function::Exp => args_signature_scalars(arg_count, 1, 0),
+        Function::Fact => args_signature_scalars(arg_count, 1, 0),
+        Function::Factdouble => args_signature_scalars(arg_count, 1, 0),
+        Function::Sign => args_signature_scalars(arg_count, 1, 0),
+        Function::Radians => args_signature_scalars(arg_count, 1, 0),
+        Function::Degrees => args_signature_scalars(arg_count, 1, 0),
+        Function::Int => args_signature_scalars(arg_count, 1, 0),
+        Function::Even => args_signature_scalars(arg_count, 1, 0),
+        Function::Odd => args_signature_scalars(arg_count, 1, 0),
+        Function::Ceiling => args_signature_scalars(arg_count, 2, 0),
+        Function::CeilingMath => args_signature_scalars(arg_count, 1, 2),
+        Function::CeilingPrecise => args_signature_scalars(arg_count, 1, 1),
+        Function::Floor => args_signature_scalars(arg_count, 2, 0),
+        Function::FloorMath => args_signature_scalars(arg_count, 1, 2),
+        Function::FloorPrecise => args_signature_scalars(arg_count, 1, 1),
+        Function::IsoCeiling => args_signature_scalars(arg_count, 1, 1),
+        Function::Mod => args_signature_scalars(arg_count, 2, 0),
+        Function::Quotient => args_signature_scalars(arg_count, 2, 0),
+        Function::Mround => args_signature_scalars(arg_count, 2, 0),
+        Function::Trunc => args_signature_scalars(arg_count, 1, 1),
+        Function::Gcd => vec![Signature::Vector; arg_count],
+        Function::Lcm => vec![Signature::Vector; arg_count],
+        Function::Base => args_signature_scalars(arg_count, 2, 1),
+        Function::Decimal => args_signature_scalars(arg_count, 2, 0),
+        Function::Roman => args_signature_scalars(arg_count, 1, 1),
+        Function::Arabic => args_signature_scalars(arg_count, 1, 0),
+        Function::Combin => args_signature_scalars(arg_count, 2, 0),
+        Function::Combina => args_signature_scalars(arg_count, 2, 0),
+        Function::Sumsq => vec![Signature::Vector; arg_count],
+
+        Function::N => args_signature_scalars(arg_count, 1, 0),
+        Function::Sheets => args_signature_scalars(arg_count, 0, 1),
+        Function::Cell => args_signature_scalars(arg_count, 1, 1),
+        Function::Info => args_signature_scalars(arg_count, 1, 1),
+
+        Function::Daverage => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dcount => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dget => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dmax => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dmin => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dsum => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dcounta => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dproduct => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dstdev => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dvar => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dvarp => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dstdevp => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
     }
 }
 
@@ -896,12 +1000,27 @@ fn static_analysis_on_function(kind: &Function, args: &[Node]) -> StaticResult {
         Function::Maxifs => not_implemented(args),
         Function::Minifs => not_implemented(args),
         Function::Date => not_implemented(args),
+        Function::Datedif => not_implemented(args),
+        Function::Datevalue => not_implemented(args),
         Function::Day => not_implemented(args),
         Function::Edate => not_implemented(args),
         Function::Month => not_implemented(args),
+        Function::Time => not_implemented(args),
+        Function::Timevalue => not_implemented(args),
+        Function::Hour => not_implemented(args),
+        Function::Minute => not_implemented(args),
+        Function::Second => not_implemented(args),
         Function::Now => not_implemented(args),
         Function::Today => not_implemented(args),
         Function::Year => not_implemented(args),
+        Function::Days => not_implemented(args),
+        Function::Days360 => not_implemented(args),
+        Function::Weekday => not_implemented(args),
+        Function::Weeknum => not_implemented(args),
+        Function::Workday => not_implemented(args),
+        Function::WorkdayIntl => not_implemented(args),
+        Function::Yearfrac => not_implemented(args),
+        Function::Isoweeknum => not_implemented(args),
         Function::Cumipmt => not_implemented(args),
         Function::Cumprinc => not_implemented(args),
         Function::Db => not_implemented(args),
@@ -990,5 +1109,61 @@ fn static_analysis_on_function(kind: &Function, args: &[Node]) -> StaticResult {
         Function::Eomonth => scalar_arguments(args),
         Function::Formulatext => not_implemented(args),
         Function::Geomean => not_implemented(args),
+        Function::Networkdays => not_implemented(args),
+        Function::NetworkdaysIntl => not_implemented(args),
+        Function::Acot => scalar_arguments(args),
+        Function::Acoth => scalar_arguments(args),
+        Function::Cot => scalar_arguments(args),
+        Function::Coth => scalar_arguments(args),
+        Function::Csc => scalar_arguments(args),
+        Function::Csch => scalar_arguments(args),
+        Function::Sec => scalar_arguments(args),
+        Function::Sech => scalar_arguments(args),
+        Function::Exp => scalar_arguments(args),
+        Function::Fact => scalar_arguments(args),
+        Function::Factdouble => scalar_arguments(args),
+        Function::Sign => scalar_arguments(args),
+        Function::Radians => scalar_arguments(args),
+        Function::Degrees => scalar_arguments(args),
+        Function::Int => scalar_arguments(args),
+        Function::Even => scalar_arguments(args),
+        Function::Odd => scalar_arguments(args),
+        Function::Ceiling => scalar_arguments(args),
+        Function::CeilingMath => scalar_arguments(args),
+        Function::CeilingPrecise => scalar_arguments(args),
+        Function::Floor => scalar_arguments(args),
+        Function::FloorMath => scalar_arguments(args),
+        Function::FloorPrecise => scalar_arguments(args),
+        Function::IsoCeiling => scalar_arguments(args),
+        Function::Mod => scalar_arguments(args),
+        Function::Quotient => scalar_arguments(args),
+        Function::Mround => scalar_arguments(args),
+        Function::Trunc => scalar_arguments(args),
+        Function::Gcd => not_implemented(args),
+        Function::Lcm => not_implemented(args),
+        Function::Base => scalar_arguments(args),
+        Function::Decimal => scalar_arguments(args),
+        Function::Roman => scalar_arguments(args),
+        Function::Arabic => scalar_arguments(args),
+        Function::Combin => scalar_arguments(args),
+        Function::Combina => scalar_arguments(args),
+        Function::Sumsq => StaticResult::Scalar,
+        Function::N => scalar_arguments(args),
+        Function::Sheets => scalar_arguments(args),
+        Function::Cell => scalar_arguments(args),
+        Function::Info => scalar_arguments(args),
+
+        Function::Dget => not_implemented(args),
+        Function::Dmax => not_implemented(args),
+        Function::Dmin => not_implemented(args),
+        Function::Dcount => not_implemented(args),
+        Function::Daverage => not_implemented(args),
+        Function::Dsum => not_implemented(args),
+        Function::Dcounta => not_implemented(args),
+        Function::Dproduct => not_implemented(args),
+        Function::Dstdev => not_implemented(args),
+        Function::Dvar => not_implemented(args),
+        Function::Dvarp => not_implemented(args),
+        Function::Dstdevp => not_implemented(args),
     }
 }

base/src/expressions/parser/stringify.rs

@@ -520,6 +520,7 @@ fn stringify(
             let x = match **left {
                 BooleanKind(_)
                 | NumberKind(_)
+                | UnaryKind { .. }
                 | StringKind(_)
                 | ReferenceKind { .. }
                 | RangeKind { .. }
@@ -535,7 +536,6 @@ fn stringify(
                 | FunctionKind { .. }
                 | InvalidFunctionKind { .. }
                 | ArrayKind(_)
-                | UnaryKind { .. }
                 | ErrorKind(_)
                 | ParseErrorKind { .. }
                 | OpSumKind { .. }
@@ -630,7 +630,6 @@ fn stringify(
                     | OpRangeKind { .. }
                     | OpConcatenateKind { .. }
                     | OpProductKind { .. }
-                    | OpPowerKind { .. }
                     | FunctionKind { .. }
                     | InvalidFunctionKind { .. }
                     | ArrayKind(_)
@@ -643,7 +642,7 @@ fn stringify(
                     | ParseErrorKind { .. }
                     | EmptyArgKind => false,
 
-                    OpSumKind { .. } | UnaryKind { .. } => true,
+                    OpPowerKind { .. } | OpSumKind { .. } | UnaryKind { .. } => true,
                 };
                 if needs_parentheses {
                     format!(

base/src/expressions/parser/tests/mod.rs

@@ -3,6 +3,7 @@ mod test_arrays;
 mod test_general;
 mod test_implicit_intersection;
 mod test_issue_155;
+mod test_issue_483;
 mod test_move_formula;
 mod test_ranges;
 mod test_stringify;

base/src/expressions/parser/tests/test_issue_483.rs

@@ -0,0 +1,27 @@
+#![allow(clippy::panic)]
+
+use std::collections::HashMap;
+
+use crate::expressions::parser::stringify::to_string;
+use crate::expressions::parser::{Node, Parser};
+use crate::expressions::types::CellReferenceRC;
+
+#[test]
+fn issue_483_parser() {
+    let worksheets = vec!["Sheet1".to_string()];
+    let mut parser = Parser::new(worksheets, vec![], HashMap::new());
+
+    // Reference cell is Sheet1!A1
+    let cell_reference = CellReferenceRC {
+        sheet: "Sheet1".to_string(),
+        row: 2,
+        column: 2,
+    };
+    let t = parser.parse("-(A1^1.22)", &cell_reference);
+    assert!(matches!(t, Node::UnaryKind { .. }));
+    assert_eq!(to_string(&t, &cell_reference), "-(A1^1.22)");
+
+    let t = parser.parse("-A1^1.22", &cell_reference);
+    assert!(matches!(t, Node::OpPowerKind { .. }));
+    assert_eq!(to_string(&t, &cell_reference), "-A1^1.22");
+}

base/src/expressions/utils/mod.rs

@@ -211,15 +211,19 @@ pub fn parse_reference_a1(r: &str) -> Option<ParsedReference> {
 pub fn is_valid_identifier(name: &str) -> bool {
     // https://support.microsoft.com/en-us/office/names-in-formulas-fc2935f9-115d-4bef-a370-3aa8bb4c91f1
     // https://github.com/MartinTrummer/excel-names/
-    // NOTE: We are being much more restrictive than Excel.
-    // In particular we do not support non ascii characters.
     let upper = name.to_ascii_uppercase();
-    let bytes = upper.as_bytes();
-    let len = bytes.len();
+    // length of chars
+    let len = upper.chars().count();
+
+    let mut chars = upper.chars();
+
     if len > 255 || len == 0 {
         return false;
     }
-    let first = bytes[0] as char;
+    let first = match chars.next() {
+        Some(ch) => ch,
+        None => return false,
+    };
     // The first character of a name must be a letter, an underscore character (_), or a backslash (\).
     if !(first.is_ascii_alphabetic() || first == '_' || first == '\\') {
         return false;
@@ -237,20 +241,10 @@ pub fn is_valid_identifier(name: &str) -> bool {
     if parse_reference_r1c1(name).is_some() {
         return false;
     }
-    let mut i = 1;
-    while i < len {
-        let ch = bytes[i] as char;
-        match ch {
-            'a'..='z' => {}
-            'A'..='Z' => {}
-            '0'..='9' => {}
-            '_' => {}
-            '.' => {}
-            _ => {
-                return false;
-            }
+    for ch in chars {
+        if !(ch.is_alphanumeric() || ch == '_' || ch == '.') {
+            return false;
         }
-        i += 1;
     }
 
     true
@@ -259,15 +253,23 @@ pub fn is_valid_identifier(name: &str) -> bool {
 fn name_needs_quoting(name: &str) -> bool {
     let chars = name.chars();
     // it contains any of these characters: ()'$,;-+{} or space
-    for char in chars {
+    for (i, char) in chars.enumerate() {
         if [' ', '(', ')', '\'', '$', ',', ';', '-', '+', '{', '}'].contains(&char) {
             return true;
         }
+        // if it starts with a number
+        if i == 0 && char.is_ascii_digit() {
+            return true;
+        }
+    }
+    if parse_reference_a1(name).is_some() {
+        // cell reference in A1 notation, e.g. B1048576 is quoted, B1048577 is not
+        return true;
+    }
+    if parse_reference_r1c1(name).is_some() {
+        // cell reference in R1C1 notation, e.g. RC, RC2, R5C, R-4C, RC-8, R, C
+        return true;
     }
-    // TODO:
-    // cell reference in A1 notation, e.g. B1048576 is quoted, B1048577 is not
-    // cell reference in R1C1 notation, e.g. RC, RC2, R5C, R-4C, RC-8, R, C
-    // integers
     false
 }
 
@@ -279,3 +281,32 @@ pub fn quote_name(name: &str) -> String {
     };
     name.to_string()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_quote_name() {
+        assert_eq!(quote_name("Sheet1"), "Sheet1");
+        assert_eq!(quote_name("Sheet 1"), "'Sheet 1'");
+        // escape and quote
+        assert_eq!(quote_name("Sheet1'"), "'Sheet1'''");
+        assert_eq!(quote_name("Data(2024)"), "'Data(2024)'");
+        assert_eq!(quote_name("Data$2024"), "'Data$2024'");
+        assert_eq!(quote_name("Data-2024"), "'Data-2024'");
+        assert_eq!(quote_name("Data+2024"), "'Data+2024'");
+        assert_eq!(quote_name("Data,2024"), "'Data,2024'");
+        assert_eq!(quote_name("Data;2024"), "'Data;2024'");
+        assert_eq!(quote_name("Data{2024}"), "'Data{2024}'");
+
+        assert_eq!(quote_name("2024"), "'2024'");
+        assert_eq!(quote_name("1Data"), "'1Data'");
+        assert_eq!(quote_name("A1"), "'A1'");
+        assert_eq!(quote_name("R1C1"), "'R1C1'");
+        assert_eq!(quote_name("MySheet"), "MySheet");
+
+        assert_eq!(quote_name("B1048576"), "'B1048576'");
+        assert_eq!(quote_name("B1048577"), "B1048577");
+    }
+}

base/src/expressions/utils/test.rs

@@ -196,6 +196,7 @@ fn test_names() {
     assert!(is_valid_identifier("_."));
     assert!(is_valid_identifier("_1"));
     assert!(is_valid_identifier("\\."));
+    assert!(is_valid_identifier("truñe"));
 
     // invalid
     assert!(!is_valid_identifier("true"));
@@ -209,7 +210,6 @@ fn test_names() {
     assert!(!is_valid_identifier("1true"));
 
     assert!(!is_valid_identifier("test€"));
-    assert!(!is_valid_identifier("truñe"));
     assert!(!is_valid_identifier("tr&ue"));
 
     assert!(!is_valid_identifier("LOG10"));

base/src/formatter/dates.rs

@@ -8,6 +8,8 @@ use crate::constants::EXCEL_DATE_BASE;
 use crate::constants::MAXIMUM_DATE_SERIAL_NUMBER;
 use crate::constants::MINIMUM_DATE_SERIAL_NUMBER;
 
+pub const DATE_OUT_OF_RANGE_MESSAGE: &str = "Out of range parameters for date";
+
 #[inline]
 fn convert_to_serial_number(date: NaiveDate) -> i32 {
     date.num_days_from_ce() - EXCEL_DATE_BASE
@@ -37,7 +39,7 @@ pub fn from_excel_date(days: i64) -> Result<NaiveDate, String> {
 pub fn date_to_serial_number(day: u32, month: u32, year: i32) -> Result<i32, String> {
     match NaiveDate::from_ymd_opt(year, month, day) {
         Some(native_date) => Ok(convert_to_serial_number(native_date)),
-        None => Err("Out of range parameters for date".to_string()),
+        None => Err(DATE_OUT_OF_RANGE_MESSAGE.to_string()),
     }
 }
 
@@ -55,7 +57,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
         return Ok(MINIMUM_DATE_SERIAL_NUMBER);
     }
     let Some(mut date) = NaiveDate::from_ymd_opt(year, 1, 1) else {
-        return Err("Out of range parameters for date".to_string());
+        return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
     };
 
     // One thing to note for example is that even if you started with a year out of range
@@ -68,7 +70,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
     // As a result, we have to run range checks as we parse the date from the biggest unit to the
     // smallest unit.
     if !is_date_within_range(date) {
-        return Err("Out of range parameters for date".to_string());
+        return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
     }
 
     date = {
@@ -80,7 +82,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
             date = date + Months::new(abs_month);
         }
         if !is_date_within_range(date) {
-            return Err("Out of range parameters for date".to_string());
+            return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
         }
         date
     };
@@ -94,7 +96,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
             date = date + Days::new(abs_day);
         }
         if !is_date_within_range(date) {
-            return Err("Out of range parameters for date".to_string());
+            return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
         }
         date
     };

base/src/formatter/format.rs

@@ -15,7 +15,7 @@ pub struct Formatted {
 
 /// Returns the vector of chars of the fractional part of a *positive* number:
 /// 3.1415926 ==> ['1', '4', '1', '5', '9', '2', '6']
-fn get_fract_part(value: f64, precision: i32) -> Vec<char> {
+fn get_fract_part(value: f64, precision: i32, int_len: usize) -> Vec<char> {
     let b = format!("{:.1$}", value.fract(), precision as usize)
         .chars()
         .collect::<Vec<char>>();
@@ -30,6 +30,12 @@ fn get_fract_part(value: f64, precision: i32) -> Vec<char> {
     if last_non_zero < 2 {
         return vec![];
     }
+    let max_len = if int_len > 15 {
+        2_usize
+    } else {
+        15_usize - int_len + 1
+    };
+    let last_non_zero = usize::min(last_non_zero, max_len + 1);
     b[2..last_non_zero].to_vec()
 }
 
@@ -154,16 +160,11 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
         ParsePart::Date(p) => {
             let tokens = &p.tokens;
             let mut text = "".to_string();
-            let date = match from_excel_date(value as i64) {
-                Ok(d) => d,
-                Err(e) => {
-                    return Formatted {
-                        text: "#VALUE!".to_owned(),
-                        color: None,
-                        error: Some(e),
-                    }
-                }
-            };
+            let time_fract = value.fract();
+            let hours = (time_fract * 24.0).floor();
+            let minutes = ((time_fract * 24.0 - hours) * 60.0).floor();
+            let seconds = ((((time_fract * 24.0 - hours) * 60.0) - minutes) * 60.0).round();
+            let date = from_excel_date(value as i64).ok();
             for token in tokens {
                 match token {
                     TextToken::Literal(c) => {
@@ -187,15 +188,44 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                     }
                     TextToken::Digit(_) => {}
                     TextToken::Period => {}
-                    TextToken::Day => {
-                        let day = date.day() as usize;
-                        text = format!("{text}{day}");
-                    }
+                    TextToken::Day => match date {
+                        Some(date) => {
+                            let day = date.day() as usize;
+                            text = format!("{text}{day}");
+                        }
+                        None => {
+                            return Formatted {
+                                text: "#VALUE!".to_owned(),
+                                color: None,
+                                error: Some(format!("Invalid date value: '{value}'")),
+                            }
+                        }
+                    },
                     TextToken::DayPadded => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let day = date.day() as usize;
                         text = format!("{text}{day:02}");
                     }
                     TextToken::DayNameShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let mut day = date.weekday().number_from_monday() as usize;
                         if day == 7 {
                             day = 0;
@@ -203,6 +233,16 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                         text = format!("{}{}", text, &locale.dates.day_names_short[day]);
                     }
                     TextToken::DayName => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let mut day = date.weekday().number_from_monday() as usize;
                         if day == 7 {
                             day = 0;
@@ -210,32 +250,144 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                         text = format!("{}{}", text, &locale.dates.day_names[day]);
                     }
                     TextToken::Month => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{text}{month}");
                     }
                     TextToken::MonthPadded => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{text}{month:02}");
                     }
                     TextToken::MonthNameShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{}{}", text, &locale.dates.months_short[month - 1]);
                     }
                     TextToken::MonthName => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{}{}", text, &locale.dates.months[month - 1]);
                     }
                     TextToken::MonthLetter => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         let months_letter = &locale.dates.months_letter[month - 1];
                         text = format!("{text}{months_letter}");
                     }
                     TextToken::YearShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         text = format!("{}{}", text, date.format("%y"));
                     }
                     TextToken::Year => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         text = format!("{}{}", text, date.year());
                     }
+                    TextToken::Hour => {
+                        let mut hour = hours as i32;
+                        if p.use_ampm {
+                            if hour == 0 {
+                                hour = 12;
+                            } else if hour > 12 {
+                                hour -= 12;
+                            }
+                        }
+                        text = format!("{text}{hour}");
+                    }
+                    TextToken::HourPadded => {
+                        let mut hour = hours as i32;
+                        if p.use_ampm {
+                            if hour == 0 {
+                                hour = 12;
+                            } else if hour > 12 {
+                                hour -= 12;
+                            }
+                        }
+                        text = format!("{text}{hour:02}");
+                    }
+                    TextToken::Second => {
+                        let second = seconds as i32;
+                        text = format!("{text}{second}");
+                    }
+                    TextToken::SecondPadded => {
+                        let second = seconds as i32;
+                        text = format!("{text}{second:02}");
+                    }
+                    TextToken::AMPM => {
+                        let ampm = if hours < 12.0 { "AM" } else { "PM" };
+                        text = format!("{text}{ampm}");
+                    }
+                    TextToken::Minute => {
+                        let minute = minutes as i32;
+                        text = format!("{text}{minute}");
+                    }
+                    TextToken::MinutePadded => {
+                        let minute = minutes as i32;
+                        text = format!("{text}{minute:02}");
+                    }
                 }
             }
             Formatted {
@@ -277,7 +429,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
             if value_abs as i64 == 0 {
                 int_part = vec![];
             }
-            let fract_part = get_fract_part(value_abs, p.precision);
+            let fract_part = get_fract_part(value_abs, p.precision, int_part.len());
             // ln is the number of digits of the integer part of the value
             let ln = int_part.len() as i32;
             // digit count is the number of digit tokens ('0', '?' and '#') to the left of the decimal point
@@ -422,6 +574,13 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                     TextToken::MonthLetter => {}
                     TextToken::YearShort => {}
                     TextToken::Year => {}
+                    TextToken::Hour => {}
+                    TextToken::HourPadded => {}
+                    TextToken::Minute => {}
+                    TextToken::MinutePadded => {}
+                    TextToken::Second => {}
+                    TextToken::SecondPadded => {}
+                    TextToken::AMPM => {}
                 }
             }
             Formatted {
@@ -591,10 +750,10 @@ fn parse_date(value: &str) -> Result<(i32, String), String> {
 /// "30.34%" => (0.3034, "0.00%")
 /// 100€ => (100, "100€")
 pub(crate) fn parse_formatted_number(
-    value: &str,
+    original: &str,
     currencies: &[&str],
 ) -> Result<(f64, Option<String>), String> {
-    let value = value.trim();
+    let value = original.trim();
     let scientific_format = "0.00E+00";
 
     // Check if it is a percentage
@@ -646,7 +805,8 @@ pub(crate) fn parse_formatted_number(
         }
     }
 
-    if let Ok((serial_number, format)) = parse_date(value) {
+    // check if it is a date. NOTE: we don't trim the original here
+    if let Ok((serial_number, format)) = parse_date(original) {
         return Ok((serial_number as f64, Some(format)));
     }
 

base/src/formatter/lexer.rs

@@ -26,19 +26,23 @@ pub enum Token {
     Scientific,    // E+
     ScientificMinus, // E-
     General,       // General
-    // Dates
+    // Dates and time
     Day,            // d
     DayPadded,      // dd
     DayNameShort,   // ddd
     DayName,        // dddd+
-    Month,          // m
-    MonthPadded,    // mm
+    Month,          // m (or minute)
+    MonthPadded,    // mm (or minute padded)
     MonthNameShort, // mmm
     MonthName,      // mmmm or mmmmmm+
     MonthLetter,    // mmmmm
     YearShort,      // y or yy
     Year,           // yyy+
-    // TODO: Hours Minutes and Seconds
+    Hour,           // h
+    HourPadded,     // hh
+    Second,         // s
+    SecondPadded,   // ss
+    AMPM,           // AM/PM (or A/P)
     ILLEGAL,
     EOF,
 }
@@ -361,8 +365,8 @@ impl Lexer {
                         self.read_next_char();
                     }
                     match m {
-                        1 => Token::Month,
-                        2 => Token::MonthPadded,
+                        1 => Token::Month,       // (or minute)
+                        2 => Token::MonthPadded, // (or minute padded)
                         3 => Token::MonthNameShort,
                         4 => Token::MonthName,
                         5 => Token::MonthLetter,
@@ -381,6 +385,63 @@ impl Lexer {
                         Token::Year
                     }
                 }
+                'h' => {
+                    let mut h = 1;
+                    while let Some('h') = self.peek_char() {
+                        h += 1;
+                        self.read_next_char();
+                    }
+                    if h == 1 {
+                        Token::Hour
+                    } else if h == 2 {
+                        Token::HourPadded
+                    } else {
+                        self.set_error("Unexpected character after 'h'");
+                        Token::ILLEGAL
+                    }
+                }
+                's' => {
+                    let mut s = 1;
+                    while let Some('s') = self.peek_char() {
+                        s += 1;
+                        self.read_next_char();
+                    }
+                    if s == 1 {
+                        Token::Second
+                    } else if s == 2 {
+                        Token::SecondPadded
+                    } else {
+                        self.set_error("Unexpected character after 's'");
+                        Token::ILLEGAL
+                    }
+                }
+                'A' | 'a' => {
+                    if let Some('M') | Some('m') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'A'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('/') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AM'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('P') | Some('p') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AM'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('M') | Some('m') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AMP'");
+                        return Token::ILLEGAL;
+                    }
+                    Token::AMPM
+                }
                 'g' | 'G' => {
                     for c in "eneral".chars() {
                         let cc = self.read_next_char();

base/src/formatter/parser.rs

@@ -27,6 +27,13 @@ pub enum TextToken {
     MonthLetter,
     YearShort,
     Year,
+    Hour,
+    HourPadded,
+    Minute,
+    MinutePadded,
+    Second,
+    SecondPadded,
+    AMPM,
 }
 pub struct NumberPart {
     pub color: Option<i32>,
@@ -45,6 +52,7 @@ pub struct NumberPart {
 
 pub struct DatePart {
     pub color: Option<i32>,
+    pub use_ampm: bool,
     pub tokens: Vec<TextToken>,
 }
 
@@ -101,6 +109,7 @@ impl Parser {
         let mut digit_count = 0;
         let mut precision = 0;
         let mut is_date = false;
+        let mut use_ampm = false;
         let mut is_number = false;
         let mut found_decimal_dot = false;
         let mut use_thousands = false;
@@ -116,6 +125,7 @@ impl Parser {
         let mut number = 'i';
         let mut index = 0;
         let mut currency = None;
+        let mut is_time = false;
 
         while token != Token::EOF && token != Token::Separator {
             let next_token = self.lexer.next_token();
@@ -200,6 +210,9 @@ impl Parser {
                     index += 1;
                 }
                 Token::Literal(value) => {
+                    if value == ':' {
+                        is_time = true;
+                    }
                     tokens.push(TextToken::Literal(value));
                 }
                 Token::Text(value) => {
@@ -236,12 +249,22 @@ impl Parser {
                     tokens.push(TextToken::MonthName);
                 }
                 Token::Month => {
-                    is_date = true;
-                    tokens.push(TextToken::Month);
+                    if is_time {
+                        // minute
+                        tokens.push(TextToken::Minute);
+                    } else {
+                        is_date = true;
+                        tokens.push(TextToken::Month);
+                    }
                 }
                 Token::MonthPadded => {
-                    is_date = true;
-                    tokens.push(TextToken::MonthPadded);
+                    if is_time {
+                        // minute padded
+                        tokens.push(TextToken::MinutePadded);
+                    } else {
+                        is_date = true;
+                        tokens.push(TextToken::MonthPadded);
+                    }
                 }
                 Token::MonthLetter => {
                     is_date = true;
@@ -255,6 +278,32 @@ impl Parser {
                     is_date = true;
                     tokens.push(TextToken::Year);
                 }
+                Token::Hour => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::Hour);
+                }
+                Token::HourPadded => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::HourPadded);
+                }
+                Token::Second => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::Second);
+                }
+                Token::SecondPadded => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::SecondPadded);
+                }
+
+                Token::AMPM => {
+                    is_date = true;
+                    use_ampm = true;
+                    tokens.push(TextToken::AMPM);
+                }
                 Token::Scientific => {
                     if !is_scientific {
                         index = 0;
@@ -282,7 +331,11 @@ impl Parser {
             if is_number {
                 return ParsePart::Error(ErrorPart {});
             }
-            ParsePart::Date(DatePart { color, tokens })
+            ParsePart::Date(DatePart {
+                color,
+                use_ampm,
+                tokens,
+            })
         } else {
             ParsePart::Number(NumberPart {
                 color,

base/src/formatter/test/mod.rs

@@ -1,2 +1,3 @@
 mod test_general;
 mod test_parse_formatted_number;
+mod test_time;

base/src/formatter/test/test_time.rs

@@ -0,0 +1,32 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{
+    formatter::format::format_number,
+    locale::{get_locale, Locale},
+};
+
+fn get_default_locale() -> &'static Locale {
+    get_locale("en").unwrap()
+}
+
+#[test]
+fn simple_test() {
+    let locale = get_default_locale();
+    let format = "h:mm AM/PM";
+    let value = 16.001_423_611_111_11; // =1/86400 => 12:02 AM
+    let formatted = format_number(value, format, locale);
+    assert_eq!(formatted.text, "12:02 AM");
+}
+
+#[test]
+fn padded_vs_unpadded() {
+    let locale = get_default_locale();
+    let padded_format = "hh:mm:ss AM/PM";
+    let unpadded_format = "h:m:s AM/PM";
+    let value = 0.25351851851851853; // => 6:05:04 AM (21904/(24*60*60)) where 21904 = 6 * 3600 + 5*60 + 4
+    let formatted = format_number(value, padded_format, locale);
+    assert_eq!(formatted.text, "06:05:04 AM");
+
+    let formatted = format_number(value, unpadded_format, locale);
+    assert_eq!(formatted.text, "6:5:4 AM");
+}

base/src/functions/database.rs

@@ -0,0 +1,946 @@
+use chrono::Datelike;
+
+use crate::{
+    calc_result::CalcResult,
+    expressions::{parser::Node, token::Error, types::CellReferenceIndex},
+    formatter::dates::date_to_serial_number,
+    Model,
+};
+
+use super::util::{compare_values, from_wildcard_to_regex, result_matches_regex};
+
+impl Model {
+    // =DAVERAGE(database, field, criteria)
+    pub(crate) fn fn_daverage(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut sum = 0.0f64;
+        let mut count = 0usize;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                        count += 1;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        CalcResult::Number(sum / count as f64)
+    }
+
+    // =DCOUNT(database, field, criteria)
+    // Counts numeric entries in the field for rows that match criteria
+    pub(crate) fn fn_dcount(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut count = 0usize;
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if matches!(v, CalcResult::Number(_)) {
+                    count += 1;
+                }
+            }
+            row += 1;
+        }
+
+        CalcResult::Number(count as f64)
+    }
+
+    // =DGET(database, field, criteria)
+    // Returns the (single) field value for the unique matching row
+    pub(crate) fn fn_dget(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut result: Option<CalcResult> = None;
+        let mut matches = 0usize;
+
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                matches += 1;
+                if matches > 1 {
+                    return CalcResult::Error {
+                        error: Error::NUM,
+                        origin: cell,
+                        message: "More than one matching record".to_string(),
+                    };
+                }
+                result = Some(self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                }));
+            }
+            row += 1;
+        }
+
+        match (matches, result) {
+            (0, _) | (_, None) => CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No matching record".to_string(),
+            },
+            (_, Some(v)) => v,
+        }
+    }
+
+    // =DMAX(database, field, criteria)
+    pub(crate) fn fn_dmax(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        self.db_extreme(args, cell, true)
+    }
+
+    // =DMIN(database, field, criteria)
+    pub(crate) fn fn_dmin(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        self.db_extreme(args, cell, false)
+    }
+
+    // =DSUM(database, field, criteria)
+    pub(crate) fn fn_dsum(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut sum = 0.0;
+
+        // skip header
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        CalcResult::Number(sum)
+    }
+
+    // =DCOUNTA(database, field, criteria)
+    // Counts non-empty entries (any type) in the field for rows that match criteria
+    pub(crate) fn fn_dcounta(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut count = 0;
+        for row in (db_left.row + 1)..=db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if !matches!(v, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                    count += 1;
+                }
+            }
+        }
+
+        CalcResult::Number(count as f64)
+    }
+
+    // =DPRODUCT(database, field, criteria)
+    pub(crate) fn fn_dproduct(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut product = 1.0f64;
+        let mut has_numeric = false;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        product *= n;
+                        has_numeric = true;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        // Excel returns 0 when no rows / no numeric values match for DPRODUCT
+        if has_numeric {
+            CalcResult::Number(product)
+        } else {
+            CalcResult::Number(0.0)
+        }
+    }
+
+    // Small internal helper for DSTDEV / DVAR
+    // Collects sum, sum of squares, and count of numeric values in the field
+    // for rows that match the criteria.
+    fn db_numeric_stats(
+        &mut self,
+        args: &[Node],
+        cell: CellReferenceIndex,
+    ) -> Result<(f64, f64, usize), CalcResult> {
+        if args.len() != 3 {
+            return Err(CalcResult::new_args_number_error(cell));
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return Err(e),
+        };
+
+        let field_col = self.resolve_db_field_column(db_left, db_right, &args[1], cell)?;
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return Err(e),
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return Err(CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            });
+        }
+
+        let mut sum = 0.0f64;
+        let mut sumsq = 0.0f64;
+        let mut count = 0usize;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                        sumsq += n * n;
+                        count += 1;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        Ok((sum, sumsq, count))
+    }
+
+    // =DSTDEV(database, field, criteria)
+    // Sample standard deviation of matching numeric values
+    pub(crate) fn fn_dstdev(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if 0 or 1 numeric values match
+        if count < 2 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "Not enough numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / (n - 1.0);
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var.sqrt())
+    }
+
+    // =DVAR(database, field, criteria)
+    // Sample variance of matching numeric values
+    pub(crate) fn fn_dvar(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if 0 or 1 numeric values match
+        if count < 2 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "Not enough numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / (n - 1.0);
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var)
+    }
+
+    // =DSTDEVP(database, field, criteria)
+    // Population standard deviation of matching numeric values
+    pub(crate) fn fn_dstdevp(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if no numeric values match
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / n;
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var.sqrt())
+    }
+
+    // =DVARP(database, field, criteria)
+    // Population variance of matching numeric values
+    pub(crate) fn fn_dvarp(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if no numeric values match
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / n;
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var)
+    }
+
+    /// Resolve the "field" (2nd arg) to an absolute column index (i32) within the sheet.
+    /// Field can be a number (1-based index) or a header name (case-insensitive).
+    /// Returns the absolute column index, not a 1-based offset within the database range.
+    fn resolve_db_field_column(
+        &mut self,
+        db_left: CellReferenceIndex,
+        db_right: CellReferenceIndex,
+        field_arg: &Node,
+        cell: CellReferenceIndex,
+    ) -> Result<i32, CalcResult> {
+        let field_column_name = match self.evaluate_node_in_context(field_arg, cell) {
+            CalcResult::String(s) => s.to_lowercase(),
+            CalcResult::Number(index) => {
+                let index = index.floor() as i32;
+                if index < 1 || db_left.column + index - 1 > db_right.column {
+                    return Err(CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Field index out of range".to_string(),
+                    });
+                }
+                return Ok(db_left.column + index - 1);
+            }
+            CalcResult::Boolean(b) => {
+                return if b {
+                    Ok(db_left.column)
+                } else {
+                    // Index 0 is out of range
+                    Err(CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Invalid field specifier".to_string(),
+                    })
+                };
+            }
+            error @ CalcResult::Error { .. } => {
+                return Err(error);
+            }
+            CalcResult::Range { .. } => {
+                return Err(CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                })
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => "".to_string(),
+            CalcResult::Array(_) => {
+                return Err(CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                })
+            }
+        };
+
+        // We search in the database a column whose header matches field_column_name
+        for column in db_left.column..=db_right.column {
+            let v = self.evaluate_cell(CellReferenceIndex {
+                sheet: db_left.sheet,
+                row: db_left.row,
+                column,
+            });
+            match &v {
+                CalcResult::String(s) => {
+                    if s.to_lowercase() == field_column_name {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Number(n) => {
+                    if field_column_name == n.to_string() {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Boolean(b) => {
+                    if field_column_name == b.to_string() {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Error { .. }
+                | CalcResult::Range { .. }
+                | CalcResult::EmptyCell
+                | CalcResult::EmptyArg
+                | CalcResult::Array(_) => {}
+            }
+        }
+
+        Err(CalcResult::Error {
+            error: Error::VALUE,
+            origin: cell,
+            message: "Field header not found".to_string(),
+        })
+    }
+
+    /// Check whether a database row matches the criteria range.
+    /// Criteria logic: OR across criteria rows; AND across columns within a row.
+    fn db_row_matches_criteria(
+        &mut self,
+        db_left: CellReferenceIndex,
+        db_right: CellReferenceIndex,
+        row: i32,
+        criteria: (CellReferenceIndex, CellReferenceIndex),
+    ) -> bool {
+        let (c_left, c_right) = criteria;
+
+        // Read criteria headers (first row of criteria range)
+        // Map header name (lowercased) -> db column (if exists)
+        let mut crit_cols: Vec<i32> = Vec::new();
+        let mut header_count = 0;
+        // We cover the criteria table:
+        //  headerA | headerB | ...
+        //  critA1  | critA2  | ...
+        //  critB1  | critB2  | ...
+        //  ...
+        for column in c_left.column..=c_right.column {
+            let cell = CellReferenceIndex {
+                sheet: c_left.sheet,
+                row: c_left.row,
+                column,
+            };
+            let criteria_header = self.evaluate_cell(cell);
+            if let Ok(s) = self.cast_to_string(criteria_header, cell) {
+                // Non-empty string header. If the header is non string we skip it
+                header_count += 1;
+                let wanted = s.to_lowercase();
+
+                // Find corresponding Database column
+                let mut found = false;
+                for db_column in db_left.column..=db_right.column {
+                    let db_header = self.evaluate_cell(CellReferenceIndex {
+                        sheet: db_left.sheet,
+                        row: db_left.row,
+                        column: db_column,
+                    });
+                    if let Ok(hs) = self.cast_to_string(db_header, cell) {
+                        if hs.to_lowercase() == wanted {
+                            crit_cols.push(db_column);
+                            found = true;
+                            break;
+                        }
+                    }
+                }
+                if !found {
+                    // that means the criteria column has no matching DB column
+                    // If the criteria condition is empty then we remove this condition
+                    // otherwise this condition can never be satisfied
+                    // We evaluate all criteria rows to see if any is non-empty
+                    let mut has_non_empty = false;
+                    for r in (c_left.row + 1)..=c_right.row {
+                        let ccell = self.evaluate_cell(CellReferenceIndex {
+                            sheet: c_left.sheet,
+                            row: r,
+                            column,
+                        });
+                        if !matches!(ccell, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                            has_non_empty = true;
+                            break;
+                        }
+                    }
+                    if has_non_empty {
+                        // This criteria column can never be satisfied
+                        header_count -= 1;
+                    }
+                }
+            };
+        }
+
+        if c_right.row <= c_left.row {
+            // If no criteria rows (only headers), everything matches
+            return true;
+        }
+
+        if header_count == 0 {
+            // If there are not "String" headers, nothing matches
+            // NB: There might be String headers that do not match any DB columns,
+            // in that case everything matches.
+            return false;
+        }
+
+        // Evaluate each criteria row (OR)
+        for r in (c_left.row + 1)..=c_right.row {
+            // AND across columns for this criteria row
+            let mut and_ok = true;
+
+            for (offset, db_col) in crit_cols.iter().enumerate() {
+                // Criteria cell
+                let ccell = self.evaluate_cell(CellReferenceIndex {
+                    sheet: c_left.sheet,
+                    row: r,
+                    column: c_left.column + offset as i32,
+                });
+
+                // Empty criteria cell -> ignored
+                if matches!(ccell, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                    continue;
+                }
+
+                // Database value for this row/column
+                let db_val = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: *db_col,
+                });
+
+                if !self.criteria_cell_matches(&db_val, &ccell) {
+                    and_ok = false;
+                    break;
+                }
+            }
+
+            if and_ok {
+                // This criteria row satisfied (OR)
+                return true;
+            }
+        }
+
+        // none matched
+        false
+    }
+
+    /// Implements Excel-like criteria matching for a single value.
+    /// Supports prefixes: <>, >=, <=, >, <, = ; wildcards * and ? for string equals.
+    fn criteria_cell_matches(&self, db_val: &CalcResult, crit_cell: &CalcResult) -> bool {
+        // Convert the criteria cell to a string for operator parsing if possible,
+        // otherwise fall back to equality via compare_values.
+
+        let mut criteria = match crit_cell {
+            CalcResult::String(s) => s.trim().to_string(),
+            CalcResult::Number(n) => {
+                // treat as equality with number
+                return match db_val {
+                    CalcResult::Number(v) => (*v - *n).abs() <= f64::EPSILON,
+                    _ => false,
+                };
+            }
+            CalcResult::Boolean(b) => {
+                // check equality with boolean
+                return match db_val {
+                    CalcResult::Boolean(v) => *v == *b,
+                    _ => false,
+                };
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => "".to_string(),
+            CalcResult::Error { .. } => return false,
+            CalcResult::Range { .. } | CalcResult::Array(_) => return false,
+        };
+
+        // Detect operator prefix
+        let mut op = "="; // default equality (with wildcard semantics for strings)
+        let prefixes = ["<>", ">=", "<=", ">", "<", "="];
+        for p in prefixes.iter() {
+            if criteria.starts_with(p) {
+                op = p;
+                criteria = criteria[p.len()..].trim().to_string();
+                break;
+            }
+        }
+
+        // Is it a number?
+        let rhs_num = criteria.parse::<f64>().ok();
+
+        // Is it a date?
+        // FIXME: We should parse dates according to locale settings
+        let rhs_date = criteria.parse::<chrono::NaiveDate>().ok();
+
+        match op {
+            ">" | ">=" | "<" | "<=" => {
+                if let Some(d) = rhs_date {
+                    // date comparison
+                    let serial = match date_to_serial_number(d.day(), d.month(), d.year()) {
+                        Ok(sn) => sn as f64,
+                        Err(_) => return false,
+                    };
+
+                    if let CalcResult::Number(n) = db_val {
+                        match op {
+                            ">" => *n > serial,
+                            ">=" => *n >= serial,
+                            "<" => *n < serial,
+                            "<=" => *n <= serial,
+                            _ => false,
+                        }
+                    } else {
+                        false
+                    }
+                } else if let Some(t) = rhs_num {
+                    // numeric comparison
+                    if let CalcResult::Number(n) = db_val {
+                        match op {
+                            ">" => *n > t,
+                            ">=" => *n >= t,
+                            "<" => *n < t,
+                            "<=" => *n <= t,
+                            _ => false,
+                        }
+                    } else {
+                        false
+                    }
+                } else {
+                    // string comparison (case-insensitive) using compare_values semantics
+                    let rhs = CalcResult::String(criteria.to_lowercase());
+                    let lhs = match db_val {
+                        CalcResult::String(s) => CalcResult::String(s.to_lowercase()),
+                        x => x.clone(),
+                    };
+                    let c = compare_values(&lhs, &rhs);
+                    match op {
+                        ">" => c > 0,
+                        ">=" => c >= 0,
+                        "<" => c < 0,
+                        "<=" => c <= 0,
+                        _ => false,
+                    }
+                }
+            }
+            "<>" => {
+                // not equal (with wildcard semantics for strings)
+                // If rhs has wildcards and db_val is string, do regex; else use compare_values != 0
+                if let CalcResult::String(s) = db_val {
+                    if criteria.contains('*') || criteria.contains('?') {
+                        if let Ok(re) = from_wildcard_to_regex(&criteria.to_lowercase(), true) {
+                            return !result_matches_regex(
+                                &CalcResult::String(s.to_lowercase()),
+                                &re,
+                            );
+                        }
+                    }
+                }
+                let rhs = if let Some(n) = rhs_num {
+                    CalcResult::Number(n)
+                } else {
+                    CalcResult::String(criteria.to_lowercase())
+                };
+                let lhs = match db_val {
+                    CalcResult::String(s) => CalcResult::String(s.to_lowercase()),
+                    x => x.clone(),
+                };
+                compare_values(&lhs, &rhs) != 0
+            }
+            _ => {
+                // equality. For strings, support wildcards (*, ?)
+                if let Some(n) = rhs_num {
+                    // numeric equals
+                    if let CalcResult::Number(m) = db_val {
+                        (*m - n).abs() <= f64::EPSILON
+                    } else {
+                        compare_values(db_val, &CalcResult::Number(n)) == 0
+                    }
+                } else {
+                    // textual/boolean equals (case-insensitive), wildcard-enabled for strings
+                    if let CalcResult::String(s) = db_val {
+                        if criteria.contains('*') || criteria.contains('?') {
+                            if let Ok(re) = from_wildcard_to_regex(&criteria.to_lowercase(), true) {
+                                return result_matches_regex(
+                                    &CalcResult::String(s.to_lowercase()),
+                                    &re,
+                                );
+                            }
+                        }
+                        // This is weird but we only need to check if "starts with" for equality
+                        return s.to_lowercase().starts_with(&criteria.to_lowercase());
+                    }
+                    // Fallback: compare_values equality
+                    compare_values(db_val, &CalcResult::String(criteria.to_lowercase())) == 0
+                }
+            }
+        }
+    }
+
+    /// Shared implementation for DMAX/DMIN
+    fn db_extreme(
+        &mut self,
+        args: &[Node],
+        cell: CellReferenceIndex,
+        want_max: bool,
+    ) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut best: Option<f64> = None;
+
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(value) = v {
+                    if value.is_finite() {
+                        best = Some(match best {
+                            None => value,
+                            Some(cur) => {
+                                if want_max {
+                                    value.max(cur)
+                                } else {
+                                    value.min(cur)
+                                }
+                            }
+                        });
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        match best {
+            Some(v) => CalcResult::Number(v),
+            None => CalcResult::Number(0.0),
+        }
+    }
+}

base/src/functions/engineering/bessel.rs

@@ -1,10 +1,12 @@
+use statrs::function::erf::{erf, erfc};
+
 use crate::{
     calc_result::CalcResult,
     expressions::{parser::Node, token::Error, types::CellReferenceIndex},
     model::Model,
 };
 
-use super::transcendental::{bessel_i, bessel_j, bessel_k, bessel_y, erf};
+use super::transcendental::{bessel_i, bessel_j, bessel_k, bessel_y};
 // https://root.cern/doc/v610/TMath_8cxx_source.html
 
 // Notice that the parameters for Bessel functions in Excel and here have inverted order
@@ -160,7 +162,7 @@ impl Model {
             Ok(f) => f,
             Err(s) => return s,
         };
-        CalcResult::Number(1.0 - erf(x))
+        CalcResult::Number(erfc(x))
     }
 
     pub(crate) fn fn_erfcprecise(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
@@ -171,6 +173,6 @@ impl Model {
             Ok(f) => f,
             Err(s) => return s,
         };
-        CalcResult::Number(1.0 - erf(x))
+        CalcResult::Number(erfc(x))
     }
 }

base/src/functions/engineering/transcendental/erf.rs

@@ -1,53 +0,0 @@
-pub(crate) fn erf(x: f64) -> f64 {
-    let cof = vec![
-        -1.3026537197817094,
-        6.419_697_923_564_902e-1,
-        1.9476473204185836e-2,
-        -9.561_514_786_808_63e-3,
-        -9.46595344482036e-4,
-        3.66839497852761e-4,
-        4.2523324806907e-5,
-        -2.0278578112534e-5,
-        -1.624290004647e-6,
-        1.303655835580e-6,
-        1.5626441722e-8,
-        -8.5238095915e-8,
-        6.529054439e-9,
-        5.059343495e-9,
-        -9.91364156e-10,
-        -2.27365122e-10,
-        9.6467911e-11,
-        2.394038e-12,
-        -6.886027e-12,
-        8.94487e-13,
-        3.13092e-13,
-        -1.12708e-13,
-        3.81e-16,
-        7.106e-15,
-        -1.523e-15,
-        -9.4e-17,
-        1.21e-16,
-        -2.8e-17,
-    ];
-
-    let mut d = 0.0;
-    let mut dd = 0.0;
-
-    let x_abs = x.abs();
-
-    let t = 2.0 / (2.0 + x_abs);
-    let ty = 4.0 * t - 2.0;
-
-    for j in (1..=cof.len() - 1).rev() {
-        let tmp = d;
-        d = ty * d - dd + cof[j];
-        dd = tmp;
-    }
-
-    let res = t * f64::exp(-x_abs * x_abs + 0.5 * (cof[0] + ty * d) - dd);
-    if x < 0.0 {
-        res - 1.0
-    } else {
-        1.0 - res
-    }
-}

base/src/functions/engineering/transcendental/mod.rs

@@ -4,7 +4,6 @@ mod bessel_j1_y1;
 mod bessel_jn_yn;
 mod bessel_k;
 mod bessel_util;
-mod erf;
 
 #[cfg(test)]
 mod test_bessel;
@@ -13,4 +12,3 @@ pub(crate) use bessel_i::bessel_i;
 pub(crate) use bessel_jn_yn::jn as bessel_j;
 pub(crate) use bessel_jn_yn::yn as bessel_y;
 pub(crate) use bessel_k::bessel_k;
-pub(crate) use erf::erf;

base/src/functions/information.rs

@@ -1,6 +1,6 @@
 use crate::{
     calc_result::CalcResult,
-    expressions::{parser::Node, token::Error, types::CellReferenceIndex},
+    expressions::{parser::Node, token::Error, types::CellReferenceIndex, utils::number_to_column},
     model::{Model, ParsedDefinedName},
 };
 
@@ -320,4 +320,150 @@ impl Model {
             message: "Invalid name".to_string(),
         }
     }
+
+    pub(crate) fn fn_n(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count != 1 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        let value = match self.evaluate_node_in_context(&args[0], cell) {
+            CalcResult::Number(n) => n,
+            CalcResult::String(_) => 0.0,
+            CalcResult::Boolean(f) => {
+                if f {
+                    1.0
+                } else {
+                    0.0
+                }
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => 0.0,
+            error @ CalcResult::Error { .. } => return error,
+            CalcResult::Range { .. } => {
+                return CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                }
+            }
+            CalcResult::Array(_) => {
+                return CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                }
+            }
+        };
+
+        CalcResult::Number(value)
+    }
+
+    pub(crate) fn fn_sheets(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count > 1 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        if arg_count == 1 {
+            return CalcResult::Error {
+                error: Error::NIMPL,
+                origin: cell,
+                message: "Sheets function with an argument is not implemented".to_string(),
+            };
+        }
+        let sheet_count = self.workbook.worksheets.len() as f64;
+        CalcResult::Number(sheet_count)
+    }
+
+    pub(crate) fn fn_cell(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count == 0 || arg_count > 2 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        let reference = if arg_count == 2 {
+            match self.evaluate_node_with_reference(&args[1], cell) {
+                CalcResult::Range { left, right: _ } => {
+                    // we just take the left cell of the range
+                    left
+                }
+                _ => {
+                    return CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Argument must be a reference".to_string(),
+                    }
+                }
+            }
+        } else {
+            CellReferenceIndex {
+                sheet: cell.sheet,
+                row: cell.row,
+                column: cell.column,
+            }
+        };
+        let info_type = match self.get_string(&args[0], cell) {
+            Ok(s) => s.to_uppercase(),
+            Err(e) => return e,
+        };
+        match info_type.as_str() {
+            "ADDRESS" => {
+                if reference.sheet != cell.sheet {
+                    return CalcResult::Error {
+                        error: Error::NIMPL,
+                        origin: cell,
+                        message: "References to other sheets not implemented".to_string(),
+                    };
+                }
+                let column = match number_to_column(reference.column) {
+                    Some(c) => c,
+                    None => {
+                        return CalcResult::Error {
+                            error: Error::VALUE,
+                            origin: cell,
+                            message: "Invalid column".to_string(),
+                        }
+                    }
+                };
+                let address = format!("${}${}", column, reference.row);
+                CalcResult::String(address)
+            }
+            "COL" => CalcResult::Number(reference.column as f64),
+            "COLOR" | "FILENAME" | "FORMAT" | "PARENTHESES" | "PREFIX" | "PROTECT" | "WIDTH" => {
+                CalcResult::Error {
+                    error: Error::VALUE,
+                    origin: cell,
+                    message: "info_type not implemented".to_string(),
+                }
+            }
+            "CONTENTS" => self.evaluate_cell(reference),
+            "ROW" => CalcResult::Number(reference.row as f64),
+            "TYPE" => {
+                let cell_type = match self.evaluate_cell(reference) {
+                    CalcResult::EmptyCell => "b",
+                    CalcResult::String(_) => "l",
+                    CalcResult::Number(_) => "v",
+                    CalcResult::Boolean(_) => "v",
+                    CalcResult::Error { .. } => "v",
+                    CalcResult::Range { .. } => "v",
+                    CalcResult::EmptyArg => "v",
+                    CalcResult::Array(_) => "v",
+                };
+                CalcResult::String(cell_type.to_string())
+            }
+            _ => CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "Invalid info_type".to_string(),
+            },
+        }
+    }
+
+    pub(crate) fn fn_info(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.is_empty() || args.len() > 2 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        CalcResult::Error {
+            error: Error::NIMPL,
+            origin: cell,
+            message: "Info function not implemented".to_string(),
+        }
+    }
 }

base/src/functions/macros.rs

@@ -68,14 +68,14 @@ macro_rules! single_number_fn {
                                 },
                                 // If String, parse to f64 then apply or #VALUE! error
                                 ArrayNode::String(s) => {
-                                    let node = match s.parse::<f64>() {
-                                        Ok(f) => match $op(f) {
+                                    let node = match self.cast_number(&s) {
+                                        Some(f) => match $op(f) {
                                             Ok(x) => ArrayNode::Number(x),
                                             Err(Error::DIV) => ArrayNode::Error(Error::DIV),
                                             Err(Error::VALUE) => ArrayNode::Error(Error::VALUE),
                                             Err(e) => ArrayNode::Error(e),
                                         },
-                                        Err(_) => ArrayNode::Error(Error::VALUE),
+                                        None => ArrayNode::Error(Error::VALUE),
                                     };
                                     data_row.push(node);
                                 }

base/src/functions/math_util.rs

@@ -0,0 +1,200 @@
+/// Parse Roman (classic or Excel variants) → number
+pub fn from_roman(s: &str) -> Result<u32, String> {
+    if s.is_empty() {
+        return Err("empty numeral".into());
+    }
+    fn val(c: char) -> Option<u32> {
+        Some(match c {
+            'I' => 1,
+            'V' => 5,
+            'X' => 10,
+            'L' => 50,
+            'C' => 100,
+            'D' => 500,
+            'M' => 1000,
+            _ => return None,
+        })
+    }
+
+    // Accept the union of subtractive pairs used by the tables above (Excel-compatible).
+    fn allowed_subtractive(a: char, b: char) -> bool {
+        matches!(
+            (a, b),
+            // classic:
+            ('I','V')|('I','X')|('X','L')|('X','C')|('C','D')|('C','M')
+            // Excel forms:
+            |('V','L')|('L','D')|('L','M') // VL, LD, LM
+            |('X','D')|('X','M')          // XD, XM
+            |('V','M')                    // VM
+            |('I','L')|('I','C')|('I','D')|('I','M') // IL, IC, ID, IM
+            |('V','D')|('V','C') // VD, VC
+        )
+    }
+
+    let chars: Vec<char> = s.chars().map(|c| c.to_ascii_uppercase()).collect();
+    let mut total = 0u32;
+    let mut i = 0usize;
+
+    // Repetition rules similar to classic Romans:
+    // V, L, D cannot repeat; I, X, C, M max 3 in a row.
+    let mut last_char: Option<char> = None;
+    let mut run_len = 0usize;
+
+    while i < chars.len() {
+        let c = chars[i];
+        let v = val(c).ok_or_else(|| format!("invalid character '{c}'"))?;
+
+        if Some(c) == last_char {
+            run_len += 1;
+            match c {
+                'V' | 'L' | 'D' => return Err(format!("invalid repetition of '{c}'")),
+                _ if run_len >= 3 => return Err(format!("invalid repetition of '{c}'")),
+                _ => {}
+            }
+        } else {
+            last_char = Some(c);
+            run_len = 0;
+        }
+
+        if i + 1 < chars.len() {
+            let c2 = chars[i + 1];
+            let v2 = val(c2).ok_or_else(|| format!("invalid character '{c2}'"))?;
+            if v < v2 {
+                if !allowed_subtractive(c, c2) {
+                    return Err(format!("invalid subtractive pair '{c}{c2}'"));
+                }
+                // Disallow stacked subtractives like IIV, XXL:
+                if run_len > 0 {
+                    return Err(format!("malformed numeral near position {i}"));
+                }
+                total += v2 - v;
+                i += 2;
+                last_char = None;
+                run_len = 0;
+                continue;
+            }
+        }
+
+        total += v;
+        i += 1;
+    }
+    Ok(total)
+}
+
+/// Classic Roman (strict) encoder used as a base for all forms.
+fn to_roman(mut n: u32) -> Result<String, String> {
+    if !(1..=3999).contains(&n) {
+        return Err("value out of range (must be 1..=3999)".into());
+    }
+
+    const MAP: &[(u32, &str)] = &[
+        (1000, "M"),
+        (900, "CM"),
+        (500, "D"),
+        (400, "CD"),
+        (100, "C"),
+        (90, "XC"),
+        (50, "L"),
+        (40, "XL"),
+        (10, "X"),
+        (9, "IX"),
+        (5, "V"),
+        (4, "IV"),
+        (1, "I"),
+    ];
+
+    let mut out = String::with_capacity(15);
+    for &(val, sym) in MAP {
+        while n >= val {
+            out.push_str(sym);
+            n -= val;
+        }
+        if n == 0 {
+            break;
+        }
+    }
+    Ok(out)
+}
+
+/// Excel/Google Sheets compatible ROMAN(number, [form]) encoder.
+/// `form`: 0..=4 (0=Classic, 4=Simplified).
+pub fn to_roman_with_form(n: u32, form: i32) -> Result<String, String> {
+    let mut s = to_roman(n)?;
+    if form == 0 {
+        return Ok(s);
+    }
+    if !(0..=4).contains(&form) {
+        return Err("form must be between 0 and 4".into());
+    }
+
+    // Base rules (apply for all f >= 1)
+    let base_rules: &[(&str, &str)] = &[
+        // C(D|M)XC -> L$1XL
+        ("CDXC", "LDXL"),
+        ("CMXC", "LMXL"),
+        // C(D|M)L -> L$1
+        ("CDL", "LD"),
+        ("CML", "LM"),
+        // X(L|C)IX -> V$1IV
+        ("XLIX", "VLIV"),
+        ("XCIX", "VCIV"),
+        // X(L|C)V -> V$1
+        ("XLV", "VL"),
+        ("XCV", "VC"),
+    ];
+
+    // Level 2 extra rules
+    let lvl2_rules: &[(&str, &str)] = &[
+        // V(L|C)IV -> I$1
+        ("VLIV", "IL"),
+        ("VCIV", "IC"),
+        // L(D|M)XL -> X$1
+        ("LDXL", "XD"),
+        ("LMXL", "XM"),
+        // L(D|M)VL -> X$1V
+        ("LDVL", "XDV"),
+        ("LMVL", "XMV"),
+        // L(D|M)IL -> X$1IX
+        ("LDIL", "XDIX"),
+        ("LMIL", "XMIX"),
+    ];
+
+    // Level 3 extra rules
+    let lvl3_rules: &[(&str, &str)] = &[
+        // X(D|M)V -> V$1
+        ("XDV", "VD"),
+        ("XMV", "VM"),
+        // X(D|M)IX -> V$1IV
+        ("XDIX", "VDIV"),
+        ("XMIX", "VMIV"),
+    ];
+
+    // Level 4 extra rules
+    let lvl4_rules: &[(&str, &str)] = &[
+        // V(D|M)IV -> I$1
+        ("VDIV", "ID"),
+        ("VMIV", "IM"),
+    ];
+
+    // Helper to apply a batch of (from -> to) globally, in order.
+    fn apply_rules(mut t: String, rules: &[(&str, &str)]) -> String {
+        for (from, to) in rules {
+            if t.contains(from) {
+                t = t.replace(from, to);
+            }
+        }
+        t
+    }
+
+    s = apply_rules(s, base_rules);
+    if form >= 2 {
+        s = apply_rules(s, lvl2_rules);
+    }
+    if form >= 3 {
+        s = apply_rules(s, lvl3_rules);
+    }
+    if form >= 4 {
+        s = apply_rules(s, lvl4_rules);
+    }
+    Ok(s)
+}

base/src/functions/mod.rs

@@ -8,6 +8,7 @@ use crate::{
 };
 
 pub(crate) mod binary_search;
+mod database;
 mod date_and_time;
 mod engineering;
 mod financial;
@@ -16,6 +17,7 @@ mod information;
 mod logical;
 mod lookup_and_reference;
 mod macros;
+mod math_util;
 mod mathematical;
 mod statistical;
 mod subtotal;
@@ -76,6 +78,43 @@ pub enum Function {
     Sumifs,
     Tan,
     Tanh,
+    Acot,
+    Acoth,
+    Cot,
+    Coth,
+    Csc,
+    Csch,
+    Sec,
+    Sech,
+    Exp,
+    Fact,
+    Factdouble,
+    Sign,
+    Radians,
+    Degrees,
+    Int,
+    Even,
+    Odd,
+    Ceiling,
+    CeilingMath,
+    CeilingPrecise,
+    Floor,
+    FloorMath,
+    FloorPrecise,
+    IsoCeiling,
+    Mod,
+    Quotient,
+    Mround,
+    Trunc,
+    Gcd,
+    Lcm,
+    Base,
+    Decimal,
+    Roman,
+    Arabic,
+    Combin,
+    Combina,
+    Sumsq,
 
     // Information
     ErrorType,
@@ -96,6 +135,11 @@ pub enum Function {
     Sheet,
     Type,
 
+    Sheets,
+    N,
+    Cell,
+    Info,
+
     // Lookup and reference
     Hlookup,
     Index,
@@ -148,13 +192,30 @@ pub enum Function {
 
     // Date and time
     Date,
+    Datedif,
+    Datevalue,
     Day,
     Edate,
     Eomonth,
     Month,
+    Time,
+    Timevalue,
+    Hour,
+    Minute,
+    Second,
     Now,
     Today,
     Year,
+    Networkdays,
+    NetworkdaysIntl,
+    Days,
+    Days360,
+    Weekday,
+    Weeknum,
+    Workday,
+    WorkdayIntl,
+    Yearfrac,
+    Isoweeknum,
 
     // Financial
     Cumipmt,
@@ -250,10 +311,24 @@ pub enum Function {
     Delta,
     Gestep,
     Subtotal,
+
+    // Database
+    Daverage,
+    Dcount,
+    Dget,
+    Dmax,
+    Dmin,
+    Dsum,
+    Dcounta,
+    Dproduct,
+    Dstdev,
+    Dvar,
+    Dvarp,
+    Dstdevp,
 }
 
 impl Function {
-    pub fn into_iter() -> IntoIter<Function, 198> {
+    pub fn into_iter() -> IntoIter<Function, 268> {
         [
             Function::And,
             Function::False,
@@ -286,12 +361,44 @@ impl Function {
             Function::Sqrt,
             Function::Sqrtpi,
             Function::Atan2,
+            Function::Acot,
+            Function::Acoth,
+            Function::Cot,
+            Function::Coth,
+            Function::Csc,
+            Function::Csch,
+            Function::Sec,
+            Function::Sech,
             Function::Power,
+            Function::Exp,
+            Function::Fact,
+            Function::Factdouble,
+            Function::Sign,
+            Function::Int,
+            Function::Even,
+            Function::Odd,
+            Function::Ceiling,
+            Function::CeilingMath,
+            Function::CeilingPrecise,
+            Function::Floor,
+            Function::FloorMath,
+            Function::FloorPrecise,
+            Function::IsoCeiling,
+            Function::Mod,
+            Function::Quotient,
+            Function::Mround,
+            Function::Trunc,
+            Function::Gcd,
+            Function::Lcm,
+            Function::Base,
+            Function::Decimal,
             Function::Max,
             Function::Min,
             Function::Product,
             Function::Rand,
             Function::Randbetween,
+            Function::Radians,
+            Function::Degrees,
             Function::Round,
             Function::Rounddown,
             Function::Roundup,
@@ -362,9 +469,26 @@ impl Function {
             Function::Month,
             Function::Eomonth,
             Function::Date,
+            Function::Datedif,
+            Function::Datevalue,
             Function::Edate,
+            Function::Networkdays,
+            Function::NetworkdaysIntl,
+            Function::Time,
+            Function::Timevalue,
+            Function::Hour,
+            Function::Minute,
+            Function::Second,
             Function::Today,
             Function::Now,
+            Function::Days,
+            Function::Days360,
+            Function::Weekday,
+            Function::Weeknum,
+            Function::Workday,
+            Function::WorkdayIntl,
+            Function::Yearfrac,
+            Function::Isoweeknum,
             Function::Pmt,
             Function::Pv,
             Function::Rate,
@@ -453,6 +577,27 @@ impl Function {
             Function::Delta,
             Function::Gestep,
             Function::Subtotal,
+            Function::Roman,
+            Function::Arabic,
+            Function::Combin,
+            Function::Combina,
+            Function::Sumsq,
+            Function::N,
+            Function::Cell,
+            Function::Info,
+            Function::Sheets,
+            Function::Daverage,
+            Function::Dcount,
+            Function::Dget,
+            Function::Dmax,
+            Function::Dmin,
+            Function::Dsum,
+            Function::Dcounta,
+            Function::Dproduct,
+            Function::Dstdev,
+            Function::Dvar,
+            Function::Dvarp,
+            Function::Dstdevp,
         ]
         .into_iter()
     }
@@ -494,6 +639,27 @@ impl Function {
             Function::Isformula => "_xlfn.ISFORMULA".to_string(),
             Function::Sheet => "_xlfn.SHEET".to_string(),
             Function::Formulatext => "_xlfn.FORMULATEXT".to_string(),
+            Function::Isoweeknum => "_xlfn.ISOWEEKNUM".to_string(),
+            Function::Ceiling => "_xlfn.CEILING".to_string(),
+            Function::CeilingMath => "_xlfn.CEILING.MATH".to_string(),
+            Function::CeilingPrecise => "_xlfn.CEILING.PRECISE".to_string(),
+            Function::FloorMath => "_xlfn.FLOOR.MATH".to_string(),
+            Function::FloorPrecise => "_xlfn.FLOOR.PRECISE".to_string(),
+            Function::IsoCeiling => "_xlfn.ISO.CEILING".to_string(),
+            Function::Base => "_xlfn.BASE".to_string(),
+            Function::Decimal => "_xlfn.DECIMAL".to_string(),
+            Function::Arabic => "_xlfn.ARABIC".to_string(),
+            Function::Combina => "_xlfn.COMBINA".to_string(),
+            Function::Sheets => "_xlfn.SHEETS".to_string(),
+            Function::Acoth => "_xlfn.ACOTH".to_string(),
+            Function::Cot => "_xlfn.COT".to_string(),
+            Function::Coth => "_xlfn.COTH".to_string(),
+            Function::Csc => "_xlfn.CSC".to_string(),
+            Function::Csch => "_xlfn.CSCH".to_string(),
+            Function::Sec => "_xlfn.SEC".to_string(),
+            Function::Sech => "_xlfn.SECH".to_string(),
+            Function::Acot => "_xlfn.ACOT".to_string(),
+
             _ => self.to_string(),
         }
     }
@@ -516,34 +682,61 @@ impl Function {
             "SWITCH" | "_XLFN.SWITCH" => Some(Function::Switch),
             "TRUE" => Some(Function::True),
             "XOR" | "_XLFN.XOR" => Some(Function::Xor),
-
             "SIN" => Some(Function::Sin),
             "COS" => Some(Function::Cos),
             "TAN" => Some(Function::Tan),
-
             "ASIN" => Some(Function::Asin),
             "ACOS" => Some(Function::Acos),
             "ATAN" => Some(Function::Atan),
-
             "SINH" => Some(Function::Sinh),
             "COSH" => Some(Function::Cosh),
             "TANH" => Some(Function::Tanh),
-
             "ASINH" => Some(Function::Asinh),
             "ACOSH" => Some(Function::Acosh),
             "ATANH" => Some(Function::Atanh),
-
+            "ACOT" | "_XLFN.ACOT" => Some(Function::Acot),
+            "COTH" | "_XLFN.COTH" => Some(Function::Coth),
+            "COT" | "_XLFN.COT" => Some(Function::Cot),
+            "CSC" | "_XLFN.CSC" => Some(Function::Csc),
+            "CSCH" | "_XLFN.CSCH" => Some(Function::Csch),
+            "SEC" | "_XLFN.SEC" => Some(Function::Sec),
+            "SECH" | "_XLFN.SECH" => Some(Function::Sech),
+            "ACOTH" | "_XLFN.ACOTH" => Some(Function::Acoth),
+            "FACT" => Some(Function::Fact),
+            "FACTDOUBLE" => Some(Function::Factdouble),
+            "EXP" => Some(Function::Exp),
+            "SIGN" => Some(Function::Sign),
+            "RADIANS" => Some(Function::Radians),
+            "DEGREES" => Some(Function::Degrees),
+            "INT" => Some(Function::Int),
+            "EVEN" => Some(Function::Even),
+            "ODD" => Some(Function::Odd),
+            "CEILING" | "_XLFN.CEILING" => Some(Function::Ceiling),
+            "CEILING.MATH" | "_XLFN.CEILING.MATH" => Some(Function::CeilingMath),
+            "CEILING.PRECISE" | "_XLFN.CEILING.PRECISE" => Some(Function::CeilingPrecise),
+            "FLOOR" => Some(Function::Floor),
+            "FLOOR.MATH" | "_XLFN.FLOOR.MATH" => Some(Function::FloorMath),
+            "FLOOR.PRECISE" | "_XLFN.FLOOR.PRECISE" => Some(Function::FloorPrecise),
+            "ISO.CEILING" | "_XLFN.ISO.CEILING" => Some(Function::IsoCeiling),
+            "MOD" => Some(Function::Mod),
+            "QUOTIENT" => Some(Function::Quotient),
+            "MROUND" => Some(Function::Mround),
+            "TRUNC" => Some(Function::Trunc),
+            "GCD" => Some(Function::Gcd),
+            "LCM" => Some(Function::Lcm),
+            "BASE" | "_XLFN.BASE" => Some(Function::Base),
+            "DECIMAL" | "_XLFN.DECIMAL" => Some(Function::Decimal),
+            "ROMAN" => Some(Function::Roman),
+            "ARABIC" | "_XLFN.ARABIC" => Some(Function::Arabic),
             "PI" => Some(Function::Pi),
             "ABS" => Some(Function::Abs),
             "SQRT" => Some(Function::Sqrt),
             "SQRTPI" => Some(Function::Sqrtpi),
             "POWER" => Some(Function::Power),
             "ATAN2" => Some(Function::Atan2),
-
             "LN" => Some(Function::Ln),
             "LOG" => Some(Function::Log),
             "LOG10" => Some(Function::Log10),
-
             "MAX" => Some(Function::Max),
             "MIN" => Some(Function::Min),
             "PRODUCT" => Some(Function::Product),
@@ -555,6 +748,9 @@ impl Function {
             "SUM" => Some(Function::Sum),
             "SUMIF" => Some(Function::Sumif),
             "SUMIFS" => Some(Function::Sumifs),
+            "COMBIN" => Some(Function::Combin),
+            "COMBINA" | "_XLFN.COMBINA" => Some(Function::Combina),
+            "SUMSQ" => Some(Function::Sumsq),
 
             // Lookup and Reference
             "CHOOSE" => Some(Function::Choose),
@@ -631,9 +827,26 @@ impl Function {
             "EOMONTH" => Some(Function::Eomonth),
             "MONTH" => Some(Function::Month),
             "DATE" => Some(Function::Date),
+            "DATEDIF" => Some(Function::Datedif),
+            "DATEVALUE" => Some(Function::Datevalue),
             "EDATE" => Some(Function::Edate),
+            "NETWORKDAYS" => Some(Function::Networkdays),
+            "NETWORKDAYS.INTL" => Some(Function::NetworkdaysIntl),
+            "TIME" => Some(Function::Time),
+            "TIMEVALUE" => Some(Function::Timevalue),
+            "HOUR" => Some(Function::Hour),
+            "MINUTE" => Some(Function::Minute),
+            "SECOND" => Some(Function::Second),
             "TODAY" => Some(Function::Today),
             "NOW" => Some(Function::Now),
+            "DAYS" | "_XLFN.DAYS" => Some(Function::Days),
+            "DAYS360" => Some(Function::Days360),
+            "WEEKDAY" => Some(Function::Weekday),
+            "WEEKNUM" => Some(Function::Weeknum),
+            "WORKDAY" => Some(Function::Workday),
+            "WORKDAY.INTL" => Some(Function::WorkdayIntl),
+            "YEARFRAC" => Some(Function::Yearfrac),
+            "ISOWEEKNUM" | "_XLFN.ISOWEEKNUM" => Some(Function::Isoweeknum),
             // Financial
             "PMT" => Some(Function::Pmt),
             "PV" => Some(Function::Pv),
@@ -725,6 +938,25 @@ impl Function {
             "GESTEP" => Some(Function::Gestep),
 
             "SUBTOTAL" => Some(Function::Subtotal),
+
+            "N" => Some(Function::N),
+            "CELL" => Some(Function::Cell),
+            "INFO" => Some(Function::Info),
+            "SHEETS" | "_XLFN.SHEETS" => Some(Function::Sheets),
+
+            "DAVERAGE" => Some(Function::Daverage),
+            "DCOUNT" => Some(Function::Dcount),
+            "DGET" => Some(Function::Dget),
+            "DMAX" => Some(Function::Dmax),
+            "DMIN" => Some(Function::Dmin),
+            "DSUM" => Some(Function::Dsum),
+            "DCOUNTA" => Some(Function::Dcounta),
+            "DPRODUCT" => Some(Function::Dproduct),
+            "DSTDEV" => Some(Function::Dstdev),
+            "DVAR" => Some(Function::Dvar),
+            "DVARP" => Some(Function::Dvarp),
+            "DSTDEVP" => Some(Function::Dstdevp),
+
             _ => None,
         }
     }
@@ -759,6 +991,14 @@ impl fmt::Display for Function {
             Function::Asinh => write!(f, "ASINH"),
             Function::Acosh => write!(f, "ACOSH"),
             Function::Atanh => write!(f, "ATANH"),
+            Function::Acot => write!(f, "ACOT"),
+            Function::Acoth => write!(f, "ACOTH"),
+            Function::Cot => write!(f, "COT"),
+            Function::Coth => write!(f, "COTH"),
+            Function::Csc => write!(f, "CSC"),
+            Function::Csch => write!(f, "CSCH"),
+            Function::Sec => write!(f, "SEC"),
+            Function::Sech => write!(f, "SECH"),
             Function::Abs => write!(f, "ABS"),
             Function::Pi => write!(f, "PI"),
             Function::Sqrt => write!(f, "SQRT"),
@@ -823,7 +1063,6 @@ impl fmt::Display for Function {
             Function::Isformula => write!(f, "ISFORMULA"),
             Function::Type => write!(f, "TYPE"),
             Function::Sheet => write!(f, "SHEET"),
-
             Function::Average => write!(f, "AVERAGE"),
             Function::Averagea => write!(f, "AVERAGEA"),
             Function::Averageif => write!(f, "AVERAGEIF"),
@@ -841,9 +1080,26 @@ impl fmt::Display for Function {
             Function::Month => write!(f, "MONTH"),
             Function::Eomonth => write!(f, "EOMONTH"),
             Function::Date => write!(f, "DATE"),
+            Function::Datedif => write!(f, "DATEDIF"),
+            Function::Datevalue => write!(f, "DATEVALUE"),
             Function::Edate => write!(f, "EDATE"),
+            Function::Networkdays => write!(f, "NETWORKDAYS"),
+            Function::NetworkdaysIntl => write!(f, "NETWORKDAYS.INTL"),
+            Function::Time => write!(f, "TIME"),
+            Function::Timevalue => write!(f, "TIMEVALUE"),
+            Function::Hour => write!(f, "HOUR"),
+            Function::Minute => write!(f, "MINUTE"),
+            Function::Second => write!(f, "SECOND"),
             Function::Today => write!(f, "TODAY"),
             Function::Now => write!(f, "NOW"),
+            Function::Days => write!(f, "DAYS"),
+            Function::Days360 => write!(f, "DAYS360"),
+            Function::Weekday => write!(f, "WEEKDAY"),
+            Function::Weeknum => write!(f, "WEEKNUM"),
+            Function::Workday => write!(f, "WORKDAY"),
+            Function::WorkdayIntl => write!(f, "WORKDAY.INTL"),
+            Function::Yearfrac => write!(f, "YEARFRAC"),
+            Function::Isoweeknum => write!(f, "ISOWEEKNUM"),
             Function::Pmt => write!(f, "PMT"),
             Function::Pv => write!(f, "PV"),
             Function::Rate => write!(f, "RATE"),
@@ -931,8 +1187,53 @@ impl fmt::Display for Function {
             Function::Convert => write!(f, "CONVERT"),
             Function::Delta => write!(f, "DELTA"),
             Function::Gestep => write!(f, "GESTEP"),
-
             Function::Subtotal => write!(f, "SUBTOTAL"),
+            Function::Exp => write!(f, "EXP"),
+            Function::Fact => write!(f, "FACT"),
+            Function::Factdouble => write!(f, "FACTDOUBLE"),
+            Function::Sign => write!(f, "SIGN"),
+            Function::Radians => write!(f, "RADIANS"),
+            Function::Degrees => write!(f, "DEGREES"),
+            Function::Int => write!(f, "INT"),
+            Function::Even => write!(f, "EVEN"),
+            Function::Odd => write!(f, "ODD"),
+            Function::Ceiling => write!(f, "CEILING"),
+            Function::CeilingMath => write!(f, "CEILING.MATH"),
+            Function::CeilingPrecise => write!(f, "CEILING.PRECISE"),
+            Function::Floor => write!(f, "FLOOR"),
+            Function::FloorMath => write!(f, "FLOOR.MATH"),
+            Function::FloorPrecise => write!(f, "FLOOR.PRECISE"),
+            Function::IsoCeiling => write!(f, "ISO.CEILING"),
+            Function::Mod => write!(f, "MOD"),
+            Function::Quotient => write!(f, "QUOTIENT"),
+            Function::Mround => write!(f, "MROUND"),
+            Function::Trunc => write!(f, "TRUNC"),
+            Function::Gcd => write!(f, "GCD"),
+            Function::Lcm => write!(f, "LCM"),
+            Function::Base => write!(f, "BASE"),
+            Function::Decimal => write!(f, "DECIMAL"),
+            Function::Roman => write!(f, "ROMAN"),
+            Function::Arabic => write!(f, "ARABIC"),
+            Function::Combin => write!(f, "COMBIN"),
+            Function::Combina => write!(f, "COMBINA"),
+            Function::Sumsq => write!(f, "SUMSQ"),
+
+            Function::N => write!(f, "N"),
+            Function::Cell => write!(f, "CELL"),
+            Function::Info => write!(f, "INFO"),
+            Function::Sheets => write!(f, "SHEETS"),
+            Function::Daverage => write!(f, "DAVERAGE"),
+            Function::Dcount => write!(f, "DCOUNT"),
+            Function::Dget => write!(f, "DGET"),
+            Function::Dmax => write!(f, "DMAX"),
+            Function::Dmin => write!(f, "DMIN"),
+            Function::Dsum => write!(f, "DSUM"),
+            Function::Dcounta => write!(f, "DCOUNTA"),
+            Function::Dproduct => write!(f, "DPRODUCT"),
+            Function::Dstdev => write!(f, "DSTDEV"),
+            Function::Dvar => write!(f, "DVAR"),
+            Function::Dvarp => write!(f, "DVARP"),
+            Function::Dstdevp => write!(f, "DSTDEVP"),
         }
     }
 }
@@ -961,7 +1262,6 @@ impl Model {
         cell: CellReferenceIndex,
     ) -> CalcResult {
         match kind {
-            // Logical
             Function::And => self.fn_and(args, cell),
             Function::False => self.fn_false(args, cell),
             Function::If => self.fn_if(args, cell),
@@ -973,34 +1273,27 @@ impl Model {
             Function::Switch => self.fn_switch(args, cell),
             Function::True => self.fn_true(args, cell),
             Function::Xor => self.fn_xor(args, cell),
-            // Math and trigonometry
             Function::Log => self.fn_log(args, cell),
             Function::Log10 => self.fn_log10(args, cell),
             Function::Ln => self.fn_ln(args, cell),
             Function::Sin => self.fn_sin(args, cell),
             Function::Cos => self.fn_cos(args, cell),
             Function::Tan => self.fn_tan(args, cell),
-
             Function::Asin => self.fn_asin(args, cell),
             Function::Acos => self.fn_acos(args, cell),
             Function::Atan => self.fn_atan(args, cell),
-
             Function::Sinh => self.fn_sinh(args, cell),
             Function::Cosh => self.fn_cosh(args, cell),
             Function::Tanh => self.fn_tanh(args, cell),
-
             Function::Asinh => self.fn_asinh(args, cell),
             Function::Acosh => self.fn_acosh(args, cell),
             Function::Atanh => self.fn_atanh(args, cell),
-
             Function::Pi => self.fn_pi(args, cell),
             Function::Abs => self.fn_abs(args, cell),
-
             Function::Sqrt => self.fn_sqrt(args, cell),
             Function::Sqrtpi => self.fn_sqrtpi(args, cell),
             Function::Atan2 => self.fn_atan2(args, cell),
             Function::Power => self.fn_power(args, cell),
-
             Function::Max => self.fn_max(args, cell),
             Function::Min => self.fn_min(args, cell),
             Function::Product => self.fn_product(args, cell),
@@ -1012,8 +1305,6 @@ impl Model {
             Function::Sum => self.fn_sum(args, cell),
             Function::Sumif => self.fn_sumif(args, cell),
             Function::Sumifs => self.fn_sumifs(args, cell),
-
-            // Lookup and Reference
             Function::Choose => self.fn_choose(args, cell),
             Function::Column => self.fn_column(args, cell),
             Function::Columns => self.fn_columns(args, cell),
@@ -1027,7 +1318,6 @@ impl Model {
             Function::Rows => self.fn_rows(args, cell),
             Function::Vlookup => self.fn_vlookup(args, cell),
             Function::Xlookup => self.fn_xlookup(args, cell),
-            // Text
             Function::Concatenate => self.fn_concatenate(args, cell),
             Function::Exact => self.fn_exact(args, cell),
             Function::Value => self.fn_value(args, cell),
@@ -1045,7 +1335,6 @@ impl Model {
             Function::Trim => self.fn_trim(args, cell),
             Function::Unicode => self.fn_unicode(args, cell),
             Function::Upper => self.fn_upper(args, cell),
-            // Information
             Function::Isnumber => self.fn_isnumber(args, cell),
             Function::Isnontext => self.fn_isnontext(args, cell),
             Function::Istext => self.fn_istext(args, cell),
@@ -1063,7 +1352,6 @@ impl Model {
             Function::Isformula => self.fn_isformula(args, cell),
             Function::Type => self.fn_type(args, cell),
             Function::Sheet => self.fn_sheet(args, cell),
-            // Statistical
             Function::Average => self.fn_average(args, cell),
             Function::Averagea => self.fn_averagea(args, cell),
             Function::Averageif => self.fn_averageif(args, cell),
@@ -1076,16 +1364,31 @@ impl Model {
             Function::Maxifs => self.fn_maxifs(args, cell),
             Function::Minifs => self.fn_minifs(args, cell),
             Function::Geomean => self.fn_geomean(args, cell),
-            // Date and Time
             Function::Year => self.fn_year(args, cell),
             Function::Day => self.fn_day(args, cell),
             Function::Eomonth => self.fn_eomonth(args, cell),
             Function::Month => self.fn_month(args, cell),
             Function::Date => self.fn_date(args, cell),
+            Function::Datedif => self.fn_datedif(args, cell),
+            Function::Datevalue => self.fn_datevalue(args, cell),
             Function::Edate => self.fn_edate(args, cell),
+            Function::Networkdays => self.fn_networkdays(args, cell),
+            Function::NetworkdaysIntl => self.fn_networkdays_intl(args, cell),
+            Function::Time => self.fn_time(args, cell),
+            Function::Timevalue => self.fn_timevalue(args, cell),
+            Function::Hour => self.fn_hour(args, cell),
+            Function::Minute => self.fn_minute(args, cell),
+            Function::Second => self.fn_second(args, cell),
             Function::Today => self.fn_today(args, cell),
             Function::Now => self.fn_now(args, cell),
-            // Financial
+            Function::Days => self.fn_days(args, cell),
+            Function::Days360 => self.fn_days360(args, cell),
+            Function::Weekday => self.fn_weekday(args, cell),
+            Function::Weeknum => self.fn_weeknum(args, cell),
+            Function::Workday => self.fn_workday(args, cell),
+            Function::WorkdayIntl => self.fn_workday_intl(args, cell),
+            Function::Yearfrac => self.fn_yearfrac(args, cell),
+            Function::Isoweeknum => self.fn_isoweeknum(args, cell),
             Function::Pmt => self.fn_pmt(args, cell),
             Function::Pv => self.fn_pv(args, cell),
             Function::Rate => self.fn_rate(args, cell),
@@ -1119,7 +1422,6 @@ impl Model {
             Function::Db => self.fn_db(args, cell),
             Function::Cumprinc => self.fn_cumprinc(args, cell),
             Function::Cumipmt => self.fn_cumipmt(args, cell),
-            // Engineering
             Function::Besseli => self.fn_besseli(args, cell),
             Function::Besselj => self.fn_besselj(args, cell),
             Function::Besselk => self.fn_besselk(args, cell),
@@ -1174,8 +1476,60 @@ impl Model {
             Function::Convert => self.fn_convert(args, cell),
             Function::Delta => self.fn_delta(args, cell),
             Function::Gestep => self.fn_gestep(args, cell),
-
             Function::Subtotal => self.fn_subtotal(args, cell),
+            Function::Acot => self.fn_acot(args, cell),
+            Function::Acoth => self.fn_acoth(args, cell),
+            Function::Cot => self.fn_cot(args, cell),
+            Function::Coth => self.fn_coth(args, cell),
+            Function::Csc => self.fn_csc(args, cell),
+            Function::Csch => self.fn_csch(args, cell),
+            Function::Sec => self.fn_sec(args, cell),
+            Function::Sech => self.fn_sech(args, cell),
+            Function::Exp => self.fn_exp(args, cell),
+            Function::Fact => self.fn_fact(args, cell),
+            Function::Factdouble => self.fn_factdouble(args, cell),
+            Function::Sign => self.fn_sign(args, cell),
+            Function::Radians => self.fn_radians(args, cell),
+            Function::Degrees => self.fn_degrees(args, cell),
+            Function::Int => self.fn_int(args, cell),
+            Function::Even => self.fn_even(args, cell),
+            Function::Odd => self.fn_odd(args, cell),
+            Function::Ceiling => self.fn_ceiling(args, cell),
+            Function::CeilingMath => self.fn_ceiling_math(args, cell),
+            Function::CeilingPrecise => self.fn_ceiling_precise(args, cell),
+            Function::Floor => self.fn_floor(args, cell),
+            Function::FloorMath => self.fn_floor_math(args, cell),
+            Function::FloorPrecise => self.fn_floor_precise(args, cell),
+            Function::IsoCeiling => self.fn_iso_ceiling(args, cell),
+            Function::Mod => self.fn_mod(args, cell),
+            Function::Quotient => self.fn_quotient(args, cell),
+            Function::Mround => self.fn_mround(args, cell),
+            Function::Trunc => self.fn_trunc(args, cell),
+            Function::Gcd => self.fn_gcd(args, cell),
+            Function::Lcm => self.fn_lcm(args, cell),
+            Function::Base => self.fn_base(args, cell),
+            Function::Decimal => self.fn_decimal(args, cell),
+            Function::Roman => self.fn_roman(args, cell),
+            Function::Arabic => self.fn_arabic(args, cell),
+            Function::Combin => self.fn_combin(args, cell),
+            Function::Combina => self.fn_combina(args, cell),
+            Function::Sumsq => self.fn_sumsq(args, cell),
+            Function::N => self.fn_n(args, cell),
+            Function::Cell => self.fn_cell(args, cell),
+            Function::Info => self.fn_info(args, cell),
+            Function::Sheets => self.fn_sheets(args, cell),
+            Function::Daverage => self.fn_daverage(args, cell),
+            Function::Dcount => self.fn_dcount(args, cell),
+            Function::Dget => self.fn_dget(args, cell),
+            Function::Dmax => self.fn_dmax(args, cell),
+            Function::Dmin => self.fn_dmin(args, cell),
+            Function::Dsum => self.fn_dsum(args, cell),
+            Function::Dcounta => self.fn_dcounta(args, cell),
+            Function::Dproduct => self.fn_dproduct(args, cell),
+            Function::Dstdev => self.fn_dstdev(args, cell),
+            Function::Dvar => self.fn_dvar(args, cell),
+            Function::Dvarp => self.fn_dvarp(args, cell),
+            Function::Dstdevp => self.fn_dstdevp(args, cell),
         }
     }
 }

base/src/functions/util.rs

@@ -1,7 +1,10 @@
 #[cfg(feature = "use_regex_lite")]
 use regex_lite as regex;
 
-use crate::{calc_result::CalcResult, expressions::token::is_english_error_string};
+use crate::{
+    calc_result::CalcResult, expressions::token::is_english_error_string,
+    number_format::to_excel_precision,
+};
 
 /// This test for exact match (modulo case).
 ///   * strings are not cast into bools or numbers
@@ -34,6 +37,8 @@ pub(crate) fn values_are_equal(left: &CalcResult, right: &CalcResult) -> bool {
 pub(crate) fn compare_values(left: &CalcResult, right: &CalcResult) -> i32 {
     match (left, right) {
         (CalcResult::Number(value1), CalcResult::Number(value2)) => {
+            let value1 = to_excel_precision(*value1, 15);
+            let value2 = to_excel_precision(*value2, 15);
             if (value2 - value1).abs() < f64::EPSILON {
                 return 0;
             }

base/src/model.rs

@@ -2068,21 +2068,7 @@ impl Model {
         scope: Option<u32>,
         formula: &str,
     ) -> Result<(), String> {
-        if !is_valid_identifier(name) {
-            return Err("Invalid defined name".to_string());
-        };
-        let name_upper = name.to_uppercase();
-        let defined_names = &self.workbook.defined_names;
-        let sheet_id = match scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
-            None => None,
-        };
-        // if the defined name already exist return error
-        for df in defined_names {
-            if df.name.to_uppercase() == name_upper && df.sheet_id == sheet_id {
-                return Err("Defined name already exists".to_string());
-            }
-        }
+        let sheet_id = self.is_valid_defined_name(name, scope, formula)?;
         self.workbook.defined_names.push(DefinedName {
             name: name.to_string(),
             formula: formula.to_string(),
@@ -2093,6 +2079,48 @@ impl Model {
         Ok(())
     }
 
+    /// Validates if a defined name can be created
+    pub fn is_valid_defined_name(
+        &self,
+        name: &str,
+        scope: Option<u32>,
+        formula: &str,
+    ) -> Result<Option<u32>, String> {
+        if !is_valid_identifier(name) {
+            return Err("Name: Invalid defined name".to_string());
+        }
+        let name_upper = name.to_uppercase();
+        let defined_names = &self.workbook.defined_names;
+        let sheet_id = match scope {
+            Some(index) => match self.workbook.worksheet(index) {
+                Ok(ws) => Some(ws.sheet_id),
+                Err(_) => return Err("Scope: Invalid sheet index".to_string()),
+            },
+            None => None,
+        };
+        // if the defined name already exist return error
+        for df in defined_names {
+            if df.name.to_uppercase() == name_upper && df.sheet_id == sheet_id {
+                return Err("Name: Defined name already exists".to_string());
+            }
+        }
+
+        // Make sure the formula is valid
+        match common::ParsedReference::parse_reference_formula(
+            None,
+            formula,
+            &self.locale,
+            |name| self.get_sheet_index_by_name(name),
+        ) {
+            Ok(_) => {}
+            Err(_) => {
+                return Err("Formula: Invalid defined name formula".to_string());
+            }
+        };
+
+        Ok(sheet_id)
+    }
+
     /// Delete defined name of name and scope
     pub fn delete_defined_name(&mut self, name: &str, scope: Option<u32>) -> Result<(), String> {
         let name_upper = name.to_uppercase();
@@ -2126,7 +2154,7 @@ impl Model {
         new_formula: &str,
     ) -> Result<(), String> {
         if !is_valid_identifier(new_name) {
-            return Err("Invalid defined name".to_string());
+            return Err("Name: Invalid defined name".to_string());
         };
         let name_upper = name.to_uppercase();
         let new_name_upper = new_name.to_uppercase();
@@ -2134,18 +2162,28 @@ impl Model {
         if name_upper != new_name_upper || scope != new_scope {
             for key in self.parsed_defined_names.keys() {
                 if key.1.to_uppercase() == new_name_upper && key.0 == new_scope {
-                    return Err("Defined name already exists".to_string());
+                    return Err("Name: Defined name already exists".to_string());
                 }
             }
         }
         let defined_names = &self.workbook.defined_names;
         let sheet_id = match scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
+            Some(index) => Some(
+                self.workbook
+                    .worksheet(index)
+                    .map_err(|_| "Scope: Invalid sheet index")?
+                    .sheet_id,
+            ),
             None => None,
         };
 
         let new_sheet_id = match new_scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
+            Some(index) => Some(
+                self.workbook
+                    .worksheet(index)
+                    .map_err(|_| "Scope: Invalid sheet index")?
+                    .sheet_id,
+            ),
             None => None,
         };
 

base/src/number_format.rs

@@ -112,29 +112,36 @@ pub fn to_precision(value: f64, precision: usize) -> f64 {
 /// ```
 /// This intends to be equivalent to the js: `${parseFloat(value.toPrecision(precision)})`
 /// See ([ecma](https://tc39.es/ecma262/#sec-number.prototype.toprecision)).
-/// FIXME: There has to be a better algorithm :/
 pub fn to_excel_precision_str(value: f64) -> String {
     to_precision_str(value, 15)
 }
+
+pub fn to_excel_precision(value: f64, precision: usize) -> f64 {
+    if !value.is_finite() {
+        return value;
+    }
+
+    let s = format!("{:.*e}", precision.saturating_sub(1), value);
+    s.parse::<f64>().unwrap_or(value)
+}
+
 pub fn to_precision_str(value: f64, precision: usize) -> String {
-    if value.is_infinite() {
-        return "inf".to_string();
+    if !value.is_finite() {
+        if value.is_infinite() {
+            return "inf".to_string();
+        } else {
+            return "NaN".to_string();
+        }
     }
-    if value.is_nan() {
-        return "NaN".to_string();
-    }
-    let exponent = value.abs().log10().floor();
-    let base = value / 10.0_f64.powf(exponent);
-    let base = format!("{0:.1$}", base, precision - 1);
-    let value = format!("{base}e{exponent}").parse::<f64>().unwrap_or({
-        // TODO: do this in a way that does not require a possible error
-        0.0
-    });
+
+    let s = format!("{:.*e}", precision.saturating_sub(1), value);
+    let parsed = s.parse::<f64>().unwrap_or(value);
+
     // I would love to use the std library. There is not a speed concern here
     // problem is it doesn't do the right thing
     // Also ryu is my favorite _modern_ algorithm
     let mut buffer = ryu::Buffer::new();
-    let text = buffer.format(value);
+    let text = buffer.format(parsed);
     // The above algorithm converts 2 to 2.0 regrettably
     if let Some(stripped) = text.strip_suffix(".0") {
         return stripped.to_string();

base/src/test/engineering/test_complex.rs

@@ -133,6 +133,7 @@ fn fn_imcot() {
     );
 }
 
+#[cfg_attr(target_os = "windows", ignore)]
 #[test]
 fn fn_imtan() {
     let mut model = new_empty_model();

base/src/test/mod.rs

@@ -7,6 +7,9 @@ mod test_column_width;
 mod test_criteria;
 mod test_currency;
 mod test_date_and_time;
+mod test_datedif_leap_month_end;
+mod test_days360_month_end;
+mod test_degrees_radians;
 mod test_error_propagation;
 mod test_fn_average;
 mod test_fn_averageifs;
@@ -27,6 +30,7 @@ mod test_fn_sum;
 mod test_fn_sumifs;
 mod test_fn_textbefore;
 mod test_fn_textjoin;
+mod test_fn_time;
 mod test_fn_unicode;
 mod test_frozen_rows_columns;
 mod test_general;
@@ -43,8 +47,11 @@ mod test_sheets;
 mod test_styles;
 mod test_trigonometric;
 mod test_true_false;
+mod test_weekday_return_types;
+mod test_weeknum_return_types;
 mod test_workbook;
 mod test_worksheet;
+mod test_yearfrac_basis;
 pub(crate) mod util;
 
 mod engineering;
@@ -62,11 +69,16 @@ mod test_geomean;
 mod test_get_cell_content;
 mod test_implicit_intersection;
 mod test_issue_155;
+mod test_issue_483;
 mod test_ln;
 mod test_log;
 mod test_log10;
+mod test_mod_quotient;
+mod test_networkdays;
+mod test_now;
 mod test_percentage;
 mod test_set_functions_error_handling;
+mod test_sheet_names;
 mod test_today;
 mod test_types;
 mod user_model;

base/src/test/test_arabic_roman

@@ -0,0 +1,27 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=ARABIC()");
+    model._set("A2", "=ARABIC(V)");
+    model._set("A3", "=ARABIC(V, 2)");
+
+    model._set("A4", "=ROMAN()");
+    model._set("A5", "=ROMAN(5)");
+    model._set("A6", "=ROMAN(5, 0)");
+    model._set("A7", "=ROMAN(5, 0, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"5");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"V");
+    assert_eq!(model._get_text("A6"), *"V");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+}

base/src/test/test_combin_combina

@@ -0,0 +1,27 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=COMBIN(5,2)");
+    model._set("A2", "=COMBINA(5,2)");
+    model._set("A3", "=COMBIN()");
+    model._set("A4", "=COMBINA()");
+    model._set("A5", "=COMBIN(2)");
+    model._set("A6", "=COMBINA(2)");
+    model._set("A5", "=COMBIN(1, 2, 3)");
+    model._set("A6", "=COMBINA(1, 2, 3)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"10");
+    assert_eq!(model._get_text("A2"), *"15");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+}

base/src/test/test_date_and_time.rs

@@ -6,6 +6,11 @@
 /// We can also enter examples that illustrate/document a part of the function
 use crate::{cell::CellValue, test::util::new_empty_model};
 
+// Excel uses a serial date system where Jan 1, 1900 = 1 (though it treats 1900 as a leap year)
+// Most test dates are documented inline, but we define boundary values here:
+const EXCEL_MAX_DATE: f64 = 2958465.0; // Dec 31, 9999 - used in boundary tests
+const EXCEL_INVALID_DATE: f64 = 2958466.0; // One day past max - used in error tests
+
 #[test]
 fn test_fn_date_arguments() {
     let mut model = new_empty_model();
@@ -216,3 +221,380 @@ fn test_date_early_dates() {
         Ok(CellValue::Number(61.0))
     );
 }
+#[test]
+fn test_days_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=DAYS(44570,44561)");
+    model._set("A2", "=DAYS(44561,44570)"); // Reversed order
+    model._set("A3", "=DAYS(44561,44561)");
+
+    // Edge cases
+    model._set("A4", "=DAYS(1,2)"); // Early dates
+    model._set(
+        "A5",
+        &format!("=DAYS({},{})", EXCEL_MAX_DATE, EXCEL_MAX_DATE - 1.0),
+    ); // Near max date
+
+    // Error cases - wrong argument count
+    model._set("A6", "=DAYS()");
+    model._set("A7", "=DAYS(44561)");
+    model._set("A8", "=DAYS(44561,44570,1)");
+
+    // Error cases - invalid dates
+    model._set("A9", "=DAYS(-1,44561)");
+    model._set("A10", &format!("=DAYS(44561,{EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"9");
+    assert_eq!(model._get_text("A2"), *"-9");
+    assert_eq!(model._get_text("A3"), *"0");
+    assert_eq!(model._get_text("A4"), *"-1"); // DAYS(1,2) = 1-2 = -1
+    assert_eq!(model._get_text("A5"), *"1");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+    assert_eq!(model._get_text("A10"), *"#NUM!");
+}
+
+#[test]
+fn test_days360_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality with different basis values
+    model._set("A1", "=DAYS360(44196,44560)"); // Default basis (US 30/360)
+    model._set("A2", "=DAYS360(44196,44560,FALSE)"); // US 30/360 explicitly
+    model._set("A3", "=DAYS360(44196,44560,TRUE)"); // European 30/360
+
+    // Same date
+    model._set("A4", "=DAYS360(44561,44561)");
+    model._set("A5", "=DAYS360(44561,44561,TRUE)");
+
+    // Reverse order (negative result)
+    model._set("A6", "=DAYS360(44560,44196)");
+    model._set("A7", "=DAYS360(44560,44196,TRUE)");
+
+    // Edge cases
+    model._set("A8", "=DAYS360(1,2)");
+    model._set("A9", "=DAYS360(1,2,FALSE)");
+
+    // Error cases - wrong argument count
+    model._set("A10", "=DAYS360()");
+    model._set("A11", "=DAYS360(44561)");
+    model._set("A12", "=DAYS360(44561,44570,TRUE,1)");
+
+    // Error cases - invalid dates
+    model._set("A13", "=DAYS360(-1,44561)");
+    model._set("A14", &format!("=DAYS360(44561,{EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"360");
+    assert_eq!(model._get_text("A2"), *"360");
+    assert_eq!(model._get_text("A3"), *"360");
+    assert_eq!(model._get_text("A4"), *"0");
+    assert_eq!(model._get_text("A5"), *"0");
+    assert_eq!(model._get_text("A6"), *"-360");
+    assert_eq!(model._get_text("A7"), *"-360");
+    assert_eq!(model._get_text("A8"), *"1");
+    assert_eq!(model._get_text("A9"), *"1");
+    assert_eq!(model._get_text("A10"), *"#ERROR!");
+    assert_eq!(model._get_text("A11"), *"#ERROR!");
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+    assert_eq!(model._get_text("A13"), *"#NUM!");
+    assert_eq!(model._get_text("A14"), *"#NUM!");
+}
+
+#[test]
+fn test_weekday_function() {
+    let mut model = new_empty_model();
+
+    // Test return_type parameter variations with one known date (Friday 44561)
+    model._set("A1", "=WEEKDAY(44561)"); // Default: Sun=1, Fri=6
+    model._set("A2", "=WEEKDAY(44561,2)"); // Mon=1, Fri=5
+    model._set("A3", "=WEEKDAY(44561,3)"); // Mon=0, Fri=4
+
+    // Test boundary days (Sun/Mon) to verify return_type logic
+    model._set("A4", "=WEEKDAY(44556,1)"); // Sunday: should be 1
+    model._set("A5", "=WEEKDAY(44556,2)"); // Sunday: should be 7
+    model._set("A6", "=WEEKDAY(44557,2)"); // Monday: should be 1
+
+    // Error cases
+    model._set("A7", "=WEEKDAY()"); // Wrong arg count
+    model._set("A8", "=WEEKDAY(44561,0)"); // Invalid return_type
+    model._set("A9", "=WEEKDAY(-1)"); // Invalid date
+
+    model.evaluate();
+
+    // Core functionality
+    assert_eq!(model._get_text("A1"), *"6"); // Friday default
+    assert_eq!(model._get_text("A2"), *"5"); // Friday Mon=1
+    assert_eq!(model._get_text("A3"), *"4"); // Friday Mon=0
+
+    // Boundary verification
+    assert_eq!(model._get_text("A4"), *"1"); // Sunday Sun=1
+    assert_eq!(model._get_text("A5"), *"7"); // Sunday Mon=1
+    assert_eq!(model._get_text("A6"), *"1"); // Monday Mon=1
+
+    // Error cases
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#VALUE!");
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+}
+
+#[test]
+fn test_weeknum_function() {
+    let mut model = new_empty_model();
+
+    // Test different return_type values (1=week starts Sunday, 2=week starts Monday)
+    model._set("A1", "=WEEKNUM(44561)"); // Default return_type=1
+    model._set("A2", "=WEEKNUM(44561,1)"); // Sunday start
+    model._set("A3", "=WEEKNUM(44561,2)"); // Monday start
+
+    // Test year boundaries
+    model._set("A4", "=WEEKNUM(43831,1)"); // Jan 1, 2020 (Wednesday)
+    model._set("A5", "=WEEKNUM(43831,2)"); // Jan 1, 2020 (Wednesday)
+    model._set("A6", "=WEEKNUM(44196,1)"); // Dec 31, 2020 (Thursday)
+    model._set("A7", "=WEEKNUM(44196,2)"); // Dec 31, 2020 (Thursday)
+
+    // Test first and last weeks of year
+    model._set("A8", "=WEEKNUM(44197,1)"); // Jan 1, 2021 (Friday)
+    model._set("A9", "=WEEKNUM(44197,2)"); // Jan 1, 2021 (Friday)
+    model._set("A10", "=WEEKNUM(44561,1)"); // Dec 31, 2021 (Friday)
+    model._set("A11", "=WEEKNUM(44561,2)"); // Dec 31, 2021 (Friday)
+
+    // Error cases - wrong argument count
+    model._set("A12", "=WEEKNUM()");
+    model._set("A13", "=WEEKNUM(44561,1,1)");
+
+    // Error cases - invalid return_type
+    model._set("A14", "=WEEKNUM(44561,0)");
+    model._set("A15", "=WEEKNUM(44561,3)");
+    model._set("A16", "=WEEKNUM(44561,-1)");
+
+    // Error cases - invalid dates
+    model._set("A17", "=WEEKNUM(-1)");
+    model._set("A18", &format!("=WEEKNUM({EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"53"); // Week 53
+    assert_eq!(model._get_text("A2"), *"53"); // Week 53 (Sunday start)
+    assert_eq!(model._get_text("A3"), *"53"); // Week 53 (Monday start)
+
+    // Year boundary tests
+    assert_eq!(model._get_text("A4"), *"1"); // Jan 1, 2020 (Sunday start)
+    assert_eq!(model._get_text("A5"), *"1"); // Jan 1, 2020 (Monday start)
+    assert_eq!(model._get_text("A6"), *"53"); // Dec 31, 2020 (Sunday start)
+    assert_eq!(model._get_text("A7"), *"53"); // Dec 31, 2020 (Monday start)
+
+    // 2021 tests
+    assert_eq!(model._get_text("A8"), *"1"); // Jan 1, 2021 (Sunday start)
+    assert_eq!(model._get_text("A9"), *"1"); // Jan 1, 2021 (Monday start)
+    assert_eq!(model._get_text("A10"), *"53"); // Dec 31, 2021 (Sunday start)
+    assert_eq!(model._get_text("A11"), *"53"); // Dec 31, 2021 (Monday start)
+
+    // Error cases
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+    assert_eq!(model._get_text("A13"), *"#ERROR!");
+    assert_eq!(model._get_text("A14"), *"#VALUE!");
+    assert_eq!(model._get_text("A15"), *"#VALUE!");
+    assert_eq!(model._get_text("A16"), *"#VALUE!");
+    assert_eq!(model._get_text("A17"), *"#NUM!");
+    assert_eq!(model._get_text("A18"), *"#NUM!");
+}
+
+#[test]
+fn test_workday_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=WORKDAY(44560,1)");
+    model._set("A2", "=WORKDAY(44561,-1)");
+    model._set("A3", "=WORKDAY(44561,0)");
+    model._set("A4", "=WORKDAY(44560,5)");
+
+    // Test with holidays
+    model._set("B1", "44561");
+    model._set("A5", "=WORKDAY(44560,1,B1)"); // Should skip the holiday
+    model._set("B2", "44562");
+    model._set("B3", "44563");
+    model._set("A6", "=WORKDAY(44560,3,B1:B3)"); // Multiple holidays
+
+    // Test starting on weekend
+    model._set("A7", "=WORKDAY(44562,1)"); // Saturday start
+    model._set("A8", "=WORKDAY(44563,1)"); // Sunday start
+
+    // Test negative workdays
+    model._set("A9", "=WORKDAY(44565,-3)"); // Go backwards 3 days
+    model._set("A10", "=WORKDAY(44565,-5,B1:B3)"); // Backwards with holidays
+
+    // Edge cases
+    model._set("A11", "=WORKDAY(1,1)"); // Early date
+    model._set("A12", "=WORKDAY(100000,10)"); // Large numbers
+
+    // Error cases - wrong argument count
+    model._set("A13", "=WORKDAY()");
+    model._set("A14", "=WORKDAY(44560)");
+    model._set("A15", "=WORKDAY(44560,1,B1,B2)");
+
+    // Error cases - invalid dates
+    model._set("A16", "=WORKDAY(-1,1)");
+    model._set("A17", &format!("=WORKDAY({EXCEL_INVALID_DATE},1)"));
+
+    // Error cases - invalid holiday dates
+    model._set("B4", "-1");
+    model._set("A18", "=WORKDAY(44560,1,B4)");
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"44561"); // 1 day forward
+    assert_eq!(model._get_text("A2"), *"44560"); // 1 day backward
+    assert_eq!(model._get_text("A3"), *"44561"); // 0 days
+    assert_eq!(model._get_text("A4"), *"44567"); // 5 days forward
+
+    // With holidays
+    assert_eq!(model._get_text("A5"), *"44564"); // Skip holiday, go to Monday
+    assert_eq!(model._get_text("A6"), *"44566"); // Skip multiple holidays
+
+    // Weekend starts
+    assert_eq!(model._get_text("A7"), *"44564"); // From Saturday
+    assert_eq!(model._get_text("A8"), *"44564"); // From Sunday
+
+    // Negative workdays
+    assert_eq!(model._get_text("A9"), *"44560"); // 3 days back
+    assert_eq!(model._get_text("A10"), *"44557"); // 5 days back with holidays
+
+    // Edge cases
+    assert_eq!(model._get_text("A11"), *"2"); // Early date
+    assert_eq!(model._get_text("A12"), *"100014"); // Large numbers
+
+    // Error cases
+    assert_eq!(model._get_text("A13"), *"#ERROR!");
+    assert_eq!(model._get_text("A14"), *"#ERROR!");
+    assert_eq!(model._get_text("A15"), *"#ERROR!");
+    assert_eq!(model._get_text("A16"), *"#NUM!");
+    assert_eq!(model._get_text("A17"), *"#NUM!");
+    assert_eq!(model._get_text("A18"), *"#NUM!"); // Invalid holiday
+}
+
+#[test]
+fn test_workday_intl_function() {
+    let mut model = new_empty_model();
+
+    // Test key weekend mask types
+    model._set("A1", "=WORKDAY.INTL(44560,1,1)"); // Numeric: standard (Sat-Sun)
+    model._set("A2", "=WORKDAY.INTL(44560,1,2)"); // Numeric: Sun-Mon
+    model._set("A3", "=WORKDAY.INTL(44560,1,\"0000001\")"); // String: Sunday only
+    model._set("A4", "=WORKDAY.INTL(44560,1,\"1100000\")"); // String: Mon-Tue
+
+    // Test with holidays
+    model._set("B1", "44561");
+    model._set("A5", "=WORKDAY.INTL(44560,2,1,B1)"); // Standard + holiday
+    model._set("A6", "=WORKDAY.INTL(44560,2,7,B1)"); // Fri-Sat + holiday
+
+    // Basic edge cases
+    model._set("A7", "=WORKDAY.INTL(44561,0,1)"); // Zero days
+    model._set("A8", "=WORKDAY.INTL(44565,-1,1)"); // Negative days
+
+    // Error cases
+    model._set("A9", "=WORKDAY.INTL()"); // Wrong arg count
+    model._set("A10", "=WORKDAY.INTL(44560,1,0)"); // Invalid weekend mask
+    model._set("A11", "=WORKDAY.INTL(44560,1,\"123\")"); // Invalid string mask
+    model._set("A12", "=WORKDAY.INTL(-1,1,1)"); // Invalid date
+
+    model.evaluate();
+
+    // Weekend mask functionality
+    assert_eq!(model._get_text("A1"), *"44561"); // Standard weekend
+    assert_eq!(model._get_text("A2"), *"44561"); // Sun-Mon weekend
+    assert_eq!(model._get_text("A3"), *"44561"); // Sunday only
+    assert_eq!(model._get_text("A4"), *"44561"); // Mon-Tue weekend
+
+    // With holidays
+    assert_eq!(model._get_text("A5"), *"44565"); // Skip holiday + standard weekend
+    assert_eq!(model._get_text("A6"), *"44564"); // Skip holiday + Fri-Sat weekend
+
+    // Edge cases
+    assert_eq!(model._get_text("A7"), *"44561"); // Zero days
+    assert_eq!(model._get_text("A8"), *"44564"); // Negative days
+
+    // Error cases
+    assert_eq!(model._get_text("A9"), *"#ERROR!");
+    assert_eq!(model._get_text("A10"), *"#NUM!");
+    assert_eq!(model._get_text("A11"), *"#VALUE!");
+    assert_eq!(model._get_text("A12"), *"#NUM!");
+}
+
+#[test]
+fn test_yearfrac_function() {
+    let mut model = new_empty_model();
+
+    // Test key basis values (not exhaustive - just verify parameter works)
+    model._set("A1", "=YEARFRAC(44561,44926)"); // Default (30/360)
+    model._set("A2", "=YEARFRAC(44561,44926,1)"); // Actual/actual
+    model._set("A3", "=YEARFRAC(44561,44926,4)"); // European 30/360
+
+    // Edge cases
+    model._set("A4", "=YEARFRAC(44561,44561,1)"); // Same date = 0
+    model._set("A6", "=YEARFRAC(44197,44562,1)"); // Exact year (2021)
+
+    // Error cases
+    model._set("A7", "=YEARFRAC()"); // Wrong arg count
+    model._set("A8", "=YEARFRAC(44561,44926,5)"); // Invalid basis
+    model._set("A9", "=YEARFRAC(-1,44926,1)"); // Invalid date
+
+    model.evaluate();
+
+    // Basic functionality (approximate values expected)
+    assert_eq!(model._get_text("A1"), *"1"); // About 1 year
+    assert_eq!(model._get_text("A2"), *"1"); // About 1 year
+    assert_eq!(model._get_text("A3"), *"1"); // About 1 year
+
+    // Edge cases
+    assert_eq!(model._get_text("A4"), *"0"); // Same date
+    assert_eq!(model._get_text("A6"), *"1"); // Exact year
+
+    // Error cases
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#NUM!"); // Invalid basis should return #NUM!
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+}
+
+#[test]
+fn test_isoweeknum_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=ISOWEEKNUM(44563)"); // Mid-week date
+    model._set("A2", "=ISOWEEKNUM(44561)"); // Year-end date
+
+    // Key ISO week boundaries (just critical cases)
+    model._set("A3", "=ISOWEEKNUM(44197)"); // Jan 1, 2021 (Fri) -> Week 53 of 2020
+    model._set("A4", "=ISOWEEKNUM(44200)"); // Jan 4, 2021 (Mon) -> Week 1 of 2021
+    model._set("A5", "=ISOWEEKNUM(44564)"); // Jan 3, 2022 (Mon) -> Week 1 of 2022
+
+    // Error cases
+    model._set("A6", "=ISOWEEKNUM()"); // Wrong arg count
+    model._set("A7", "=ISOWEEKNUM(-1)"); // Invalid date
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"52");
+    assert_eq!(model._get_text("A2"), *"52");
+
+    // ISO week boundaries
+    assert_eq!(model._get_text("A3"), *"53"); // Week 53 of previous year
+    assert_eq!(model._get_text("A4"), *"1"); // Week 1 of current year
+    assert_eq!(model._get_text("A5"), *"1"); // Week 1 of next year
+
+    // Error cases
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#NUM!");
+}

base/src/test/test_datedif_leap_month_end.rs

@@ -0,0 +1,33 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_datedif_yd_leap_year_edge_cases() {
+    let mut model = new_empty_model();
+
+    // 29 Feb 2020 → 28 Feb 2021   (should be 0 days)
+    model._set("A1", "=DATEDIF(\"29/2/2020\", \"28/2/2021\", \"YD\")");
+
+    // 29 Feb 2020 → 1 Mar 2021    (should be 1 day)
+    model._set("A2", "=DATEDIF(\"29/2/2020\", \"2021-03-01\", \"YD\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"0");
+    assert_eq!(model._get_text("A2"), *"1");
+}
+
+#[test]
+fn test_datedif_md_month_end_edge_cases() {
+    let mut model = new_empty_model();
+
+    // 31 Jan 2021 → 28 Feb 2021 (non-leap) => 28
+    model._set("B1", "=DATEDIF(\"31/1/2021\", \"28/2/2021\", \"MD\")");
+
+    // 31 Jan 2020 → 29 Feb 2020 (leap) => 29
+    model._set("B2", "=DATEDIF(\"31/1/2020\", \"29/2/2020\", \"MD\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("B1"), *"28");
+    assert_eq!(model._get_text("B2"), *"29");
+}

base/src/test/test_days360_month_end.rs

@@ -0,0 +1,43 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_days360_month_end_us() {
+    let mut model = new_empty_model();
+
+    // 31 Jan 2021 -> 28 Feb 2021 (non-leap)
+    model._set("A1", "=DAYS360(DATE(2021,1,31),DATE(2021,2,28))");
+
+    // 31 Jan 2020 -> 28 Feb 2020 (leap year – not last day of Feb)
+    model._set("A2", "=DAYS360(DATE(2020,1,31),DATE(2020,2,28))");
+
+    // 28 Feb 2020 -> 31 Mar 2020 (leap year span crossing month ends)
+    model._set("A3", "=DAYS360(DATE(2020,2,28),DATE(2020,3,31))");
+
+    // 30 Apr 2021 -> 31 May 2021 (end-of-month adjustment rule)
+    model._set("A4", "=DAYS360(DATE(2021,4,30),DATE(2021,5,31))");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"30");
+    assert_eq!(model._get_text("A2"), *"28");
+    assert_eq!(model._get_text("A3"), *"33");
+    assert_eq!(model._get_text("A4"), *"30");
+}
+
+#[test]
+fn test_days360_month_end_european() {
+    let mut model = new_empty_model();
+
+    // European basis = TRUE (or 1)
+    model._set("B1", "=DAYS360(DATE(2021,1,31),DATE(2021,2,28),TRUE)");
+
+    model._set("B2", "=DAYS360(DATE(2020,1,31),DATE(2020,2,29),TRUE)");
+
+    model._set("B3", "=DAYS360(DATE(2021,8,31),DATE(2021,9,30),TRUE)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("B1"), *"28");
+    assert_eq!(model._get_text("B2"), *"29");
+    assert_eq!(model._get_text("B3"), *"30");
+}

base/src/test/test_degrees_radians.rs

@@ -0,0 +1,22 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_degrees_radians_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=DEGREES()");
+    model._set("A2", "=RADIANS()");
+    model._set("A3", "=RADIANS(180)");
+    model._set("A4", "=RADIANS(180, 2)");
+    model._set("A5", "=DEGREES(RADIANS(180))");
+    model._set("A6", "=DEGREES(1, 2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"3.141592654");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"180");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_even_odd

@@ -0,0 +1,23 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=EVEN(2)");
+    model._set("A2", "=ODD(2)");
+    model._set("A3", "=EVEN()");
+    model._set("A4", "=ODD()");
+    model._set("A5", "=EVEN(1, 2)");
+    model._set("A6", "=ODD(1, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"3");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_exp_sign.rs

@@ -0,0 +1,26 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=EXP()");
+    model._set("A2", "=SIGN()");
+
+    model._set("A3", "=EXP(0)");
+    model._set("A4", "=SIGN(-10)");
+
+    model._set("A5", "=EXP(1, 2)");
+    model._set("A6", "=SIGN(1, 2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A3"), *"1");
+    assert_eq!(model._get_text("A4"), *"-1");
+
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_fn_datevalue_datedif.rs

@@ -0,0 +1,182 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+use crate::types::Cell;
+
+// Helper to evaluate a formula and return the formatted text
+fn eval_formula(formula: &str) -> String {
+    let mut model = new_empty_model();
+    model._set("A1", formula);
+    model.evaluate();
+    model._get_text("A1")
+}
+
+// Helper that evaluates a formula and returns the raw value of A1 as a Result<f64, String>
+fn eval_formula_raw_number(formula: &str) -> Result<f64, String> {
+    let mut model = new_empty_model();
+    model._set("A1", formula);
+    model.evaluate();
+    match model._get_cell("A1") {
+        Cell::NumberCell { v, .. } => Ok(*v),
+        Cell::BooleanCell { v, .. } => Ok(if *v { 1.0 } else { 0.0 }),
+        Cell::ErrorCell { ei, .. } => Err(format!("{}", ei)),
+        _ => Err(model._get_text("A1")),
+    }
+}
+
+#[test]
+fn test_datevalue_basic_numeric() {
+    // DATEVALUE should return the serial number representing the date, **not** a formatted date
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2/1/2023\")").unwrap(),
+        44958.0
+    );
+}
+
+#[test]
+fn test_datevalue_mmdd_with_leading_zero() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"02/01/2023\")").unwrap(),
+        44958.0
+    ); // 1-Feb-2023
+}
+
+#[test]
+fn test_datevalue_iso() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2023-01-02\")").unwrap(),
+        44928.0
+    );
+}
+
+#[test]
+fn test_datevalue_month_name() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2-Jan-23\")").unwrap(),
+        44928.0
+    );
+}
+
+#[test]
+fn test_datevalue_ambiguous_ddmm() {
+    // 01/02/2023 interpreted as MM/DD -> 2-Jan-2023
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"01/02/2023\")").unwrap(),
+        44929.0
+    );
+}
+
+#[test]
+fn test_datevalue_ddmm_unambiguous() {
+    // 15/01/2023 should be 15-Jan-2023 since 15 cannot be month
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"15/01/2023\")").unwrap(),
+        44941.0
+    );
+}
+
+#[test]
+fn test_datevalue_leap_day() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"29/02/2020\")").unwrap(),
+        43890.0
+    );
+}
+
+#[test]
+fn test_datevalue_year_first_text_month() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2023/Jan/15\")").unwrap(),
+        44941.0
+    );
+}
+
+#[test]
+fn test_datevalue_mmdd_with_day_gt_12() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"6/15/2021\")").unwrap(),
+        44373.0
+    );
+}
+
+#[test]
+fn test_datevalue_error_conditions() {
+    let cases = [
+        "=DATEVALUE(\"31/04/2023\")",   // invalid day (Apr has 30 days)
+        "=DATEVALUE(\"13/13/2023\")",   // invalid month
+        "=DATEVALUE(\"not a date\")",   // non-date text
+    ];
+    for formula in cases {
+        let result = eval_formula(formula);
+        assert_eq!(result, *"#VALUE!", "Expected #VALUE! for {}", formula);
+    }
+}
+
+// Helper to set and evaluate a single DATEDIF call
+fn eval_datedif(unit: &str) -> String {
+    let mut model = new_empty_model();
+    let formula = format!("=DATEDIF(\"2020-01-01\", \"2021-06-15\", \"{}\")", unit);
+    model._set("A1", &formula);
+    model.evaluate();
+    model._get_text("A1")
+}
+
+#[test]
+fn test_datedif_y() {
+    assert_eq!(eval_datedif("Y"), *"1");
+}
+
+#[test]
+fn test_datedif_m() {
+    assert_eq!(eval_datedif("M"), *"17");
+}
+
+#[test]
+fn test_datedif_d() {
+    assert_eq!(eval_datedif("D"), *"531");
+}
+
+#[test]
+fn test_datedif_ym() {
+    assert_eq!(eval_datedif("YM"), *"5");
+}
+
+#[test]
+fn test_datedif_yd() {
+    assert_eq!(eval_datedif("YD"), *"165");
+}
+
+#[test]
+fn test_datedif_md() {
+    assert_eq!(eval_datedif("MD"), *"14");
+}
+
+#[test]
+fn test_datedif_edge_and_error_cases() {
+    let mut model = new_empty_model();
+    // Leap-year spanning
+    model._set("A1", "=DATEDIF(\"28/2/2020\", \"1/3/2020\", \"D\")");
+    // End date before start date => #NUM!
+    model._set("A2", "=DATEDIF(\"1/2/2021\", \"1/1/2021\", \"D\")");
+    // Invalid unit => #VALUE!
+    model._set("A3", "=DATEDIF(\"1/1/2020\", \"1/1/2021\", \"Z\")");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"#NUM!");
+    assert_eq!(model._get_text("A3"), *"#VALUE!");
+}
+
+#[test]
+fn test_datedif_mixed_case_unit() {
+    assert_eq!(eval_datedif("yD"), *"165"); // mixed-case should work
+}
+
+#[test]
+fn test_datedif_error_propagation() {
+    // Invalid date in arguments should propagate #VALUE!
+    let mut model = new_empty_model();
+    model._set("A1", "=DATEDIF(\"bad\", \"bad\", \"Y\")");
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"#VALUE!");
+}

base/src/test/test_fn_datevalue_timevalue.rs

@@ -0,0 +1,24 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn datevalue_timevalue_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=DATEVALUE()");
+    model._set("A2", "=TIMEVALUE()");
+    model._set("A3", "=DATEVALUE("2000-01-01")")
+    model._set("A4", "=TIMEVALUE("12:00:00")")
+    model._set("A5", "=DATEVALUE(1,2)");
+    model._set("A6", "=TIMEVALUE(1,2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"36526");
+    assert_eq!(model._get_text("A4"), *"0.5");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}
+
+

base/src/test/test_fn_time.rs

@@ -0,0 +1,520 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+// Helper constants for common time values with detailed documentation
+const MIDNIGHT: &str = "0"; // 00:00:00 = 0/24 = 0
+const NOON: &str = "0.5"; // 12:00:00 = 12/24 = 0.5
+const TIME_14_30: &str = "0.604166667"; // 14:30:00 = 14.5/24 ≈ 0.604166667
+const TIME_14_30_45: &str = "0.6046875"; // 14:30:45 = 14.5125/24 = 0.6046875
+const TIME_14_30_59: &str = "0.604849537"; // 14:30:59 (from floored fractional inputs)
+const TIME_23_59_59: &str = "0.999988426"; // 23:59:59 = 23.99972.../24 ≈ 0.999988426
+
+// Excel documentation test values with explanations
+const TIME_2_24_AM: &str = "0.1"; // 2:24 AM = 2.4/24 = 0.1
+const TIME_2_PM: &str = "0.583333333"; // 2:00 PM = 14/24 ≈ 0.583333333
+const TIME_6_45_PM: &str = "0.78125"; // 6:45 PM = 18.75/24 = 0.78125
+const TIME_6_35_AM: &str = "0.274305556"; // 6:35 AM = 6.583333.../24 ≈ 0.274305556
+const TIME_2_30_AM: &str = "0.104166667"; // 2:30 AM = 2.5/24 ≈ 0.104166667
+const TIME_1_AM: &str = "0.041666667"; // 1:00 AM = 1/24 ≈ 0.041666667
+const TIME_9_PM: &str = "0.875"; // 9:00 PM = 21/24 = 0.875
+const TIME_2_AM: &str = "0.083333333"; // 2:00 AM = 2/24 ≈ 0.083333333
+                                       // Additional helper: 1-second past midnight (00:00:01)
+const TIME_00_00_01: &str = "0.000011574"; // 1 second = 1/86400 ≈ 0.000011574
+
+/// Helper function to set up and evaluate a model with time expressions
+fn test_time_expressions(expressions: &[(&str, &str)]) -> crate::model::Model {
+    let mut model = new_empty_model();
+    for (cell, formula) in expressions {
+        model._set(cell, formula);
+    }
+    model.evaluate();
+    model
+}
+
+/// Helper function to test component extraction for a given time value
+/// Returns (hour, minute, second) as strings
+fn test_component_extraction(time_value: &str) -> (String, String, String) {
+    let model = test_time_expressions(&[
+        ("A1", &format!("=HOUR({time_value})")),
+        ("B1", &format!("=MINUTE({time_value})")),
+        ("C1", &format!("=SECOND({time_value})")),
+    ]);
+    (
+        model._get_text("A1").to_string(),
+        model._get_text("B1").to_string(),
+        model._get_text("C1").to_string(),
+    )
+}
+
+#[test]
+fn test_excel_timevalue_compatibility() {
+    // Test cases based on Excel's official documentation and examples
+    let model = test_time_expressions(&[
+        // Excel documentation examples
+        ("A1", "=TIMEVALUE(\"2:24 AM\")"), // Should be 0.1
+        ("A2", "=TIMEVALUE(\"2 PM\")"),    // Should be 0.583333... (14/24)
+        ("A3", "=TIMEVALUE(\"6:45 PM\")"), // Should be 0.78125 (18.75/24)
+        ("A4", "=TIMEVALUE(\"18:45\")"),   // Same as above, 24-hour format
+        // Date-time format (date should be ignored)
+        ("B1", "=TIMEVALUE(\"22-Aug-2011 6:35 AM\")"), // Should be ~0.2743
+        ("B2", "=TIMEVALUE(\"2023-01-01 14:30:00\")"), // Should be 0.604166667
+        // Edge cases that Excel should support
+        ("C1", "=TIMEVALUE(\"12:00 AM\")"),    // Midnight: 0
+        ("C2", "=TIMEVALUE(\"12:00 PM\")"),    // Noon: 0.5
+        ("C3", "=TIMEVALUE(\"11:59:59 PM\")"), // Almost midnight: 0.999988426
+        // Single digit variations
+        ("D1", "=TIMEVALUE(\"1 AM\")"),  // 1:00 AM
+        ("D2", "=TIMEVALUE(\"9 PM\")"),  // 9:00 PM
+        ("D3", "=TIMEVALUE(\"12 AM\")"), // Midnight
+        ("D4", "=TIMEVALUE(\"12 PM\")"), // Noon
+    ]);
+
+    // Excel documentation examples - verify exact values
+    assert_eq!(model._get_text("A1"), *TIME_2_24_AM); // 2:24 AM
+    assert_eq!(model._get_text("A2"), *TIME_2_PM); // 2 PM = 14:00
+    assert_eq!(model._get_text("A3"), *TIME_6_45_PM); // 6:45 PM = 18:45
+    assert_eq!(model._get_text("A4"), *TIME_6_45_PM); // 18:45 (24-hour)
+
+    // Date-time formats (date ignored, extract time only)
+    assert_eq!(model._get_text("B1"), *TIME_6_35_AM); // 6:35 AM ≈ 0.2743
+    assert_eq!(model._get_text("B2"), *TIME_14_30); // 14:30:00
+
+    // Edge cases
+    assert_eq!(model._get_text("C1"), *MIDNIGHT); // 12:00 AM = 00:00
+    assert_eq!(model._get_text("C2"), *NOON); // 12:00 PM = 12:00
+    assert_eq!(model._get_text("C3"), *TIME_23_59_59); // 11:59:59 PM
+
+    // Single digit hours
+    assert_eq!(model._get_text("D1"), *TIME_1_AM); // 1:00 AM
+    assert_eq!(model._get_text("D2"), *TIME_9_PM); // 9:00 PM = 21:00
+    assert_eq!(model._get_text("D3"), *MIDNIGHT); // 12 AM = 00:00
+    assert_eq!(model._get_text("D4"), *NOON); // 12 PM = 12:00
+}
+
+#[test]
+fn test_time_function_basic_cases() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME(0,0,0)"),    // Midnight
+        ("A2", "=TIME(12,0,0)"),   // Noon
+        ("A3", "=TIME(14,30,0)"),  // 2:30 PM
+        ("A4", "=TIME(23,59,59)"), // Max time
+    ]);
+
+    assert_eq!(model._get_text("A1"), *MIDNIGHT);
+    assert_eq!(model._get_text("A2"), *NOON);
+    assert_eq!(model._get_text("A3"), *TIME_14_30);
+    assert_eq!(model._get_text("A4"), *TIME_23_59_59);
+}
+
+#[test]
+fn test_time_function_normalization() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME(25,0,0)"),         // Hours > 24 wrap around
+        ("A2", "=TIME(48,0,0)"),         // 48 hours = 0 (2 full days)
+        ("A3", "=TIME(0,90,0)"),         // 90 minutes = 1.5 hours
+        ("A4", "=TIME(0,0,90)"),         // 90 seconds = 1.5 minutes
+        ("A5", "=TIME(14.9,30.9,59.9)"), // Fractional inputs floored to 14:30:59
+    ]);
+
+    assert_eq!(model._get_text("A1"), *TIME_1_AM); // 1:00:00
+    assert_eq!(model._get_text("A2"), *MIDNIGHT); // 0:00:00
+    assert_eq!(model._get_text("A3"), *"0.0625"); // 1:30:00
+    assert_eq!(model._get_text("A4"), *"0.001041667"); // 0:01:30
+    assert_eq!(model._get_text("A5"), *TIME_14_30_59); // 14:30:59 (floored)
+}
+
+#[test]
+fn test_time_function_precision_edge_cases() {
+    let model = test_time_expressions(&[
+        // High precision fractional seconds
+        ("A1", "=TIME(14,30,45.999)"), // Fractional seconds should be floored
+        ("A2", "=SECOND(TIME(14,30,45.999))"), // Should extract 45, not 46
+        // Very large normalization values
+        ("B1", "=TIME(999,999,999)"), // Extreme normalization test
+        ("B2", "=HOUR(999.5)"),       // Multiple days, extract hour from fractional part
+        ("B3", "=MINUTE(999.75)"),    // Multiple days, extract minute
+        // Boundary conditions at rollover points
+        ("C1", "=TIME(24,60,60)"), // Should normalize to next day (00:01:00)
+        ("C2", "=HOUR(0.999999999)"), // Almost 24 hours should be 23
+        ("C3", "=MINUTE(0.999999999)"), // Almost 24 hours, extract minutes
+        ("C4", "=SECOND(0.999999999)"), // Almost 24 hours, extract seconds
+        // Precision at boundaries
+        ("D1", "=TIME(23,59,59.999)"), // Very close to midnight
+        ("D2", "=TIME(0,0,0.001)"),    // Just after midnight
+    ]);
+
+    // Fractional seconds are floored
+    assert_eq!(model._get_text("A2"), *"45"); // 45.999 floored to 45
+
+    // Multiple days should work with rem_euclid
+    assert_eq!(model._get_text("B2"), *"12"); // 999.5 days, hour = 12 (noon)
+
+    // Boundary normalization
+    assert_eq!(model._get_text("C1"), *"0.042361111"); // 24:60:60 = 01:01:00 (normalized)
+    assert_eq!(model._get_text("C2"), *"23"); // Almost 24 hours = 23:xx:xx
+
+    // High precision should be handled correctly
+    let result_d1 = model._get_text("D1").parse::<f64>().unwrap();
+    assert!(result_d1 < 1.0 && result_d1 > 0.999); // Very close to but less than 1.0
+}
+
+#[test]
+fn test_time_function_errors() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME()"),          // Wrong arg count
+        ("A2", "=TIME(12)"),        // Wrong arg count
+        ("A3", "=TIME(12,30,0,0)"), // Wrong arg count
+        ("B1", "=TIME(-1,0,0)"),    // Negative hour
+        ("B2", "=TIME(0,-1,0)"),    // Negative minute
+        ("B3", "=TIME(0,0,-1)"),    // Negative second
+    ]);
+
+    // Wrong argument count
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    // Negative values should return #NUM! error
+    assert_eq!(model._get_text("B1"), *"#NUM!");
+    assert_eq!(model._get_text("B2"), *"#NUM!");
+    assert_eq!(model._get_text("B3"), *"#NUM!");
+}
+
+#[test]
+fn test_timevalue_function_formats() {
+    let model = test_time_expressions(&[
+        // Basic formats
+        ("A1", "=TIMEVALUE(\"14:30\")"),
+        ("A2", "=TIMEVALUE(\"14:30:45\")"),
+        ("A3", "=TIMEVALUE(\"00:00:00\")"),
+        // AM/PM formats
+        ("B1", "=TIMEVALUE(\"2:30 PM\")"),
+        ("B2", "=TIMEVALUE(\"2:30 AM\")"),
+        ("B3", "=TIMEVALUE(\"12:00 PM\")"), // Noon
+        ("B4", "=TIMEVALUE(\"12:00 AM\")"), // Midnight
+        // Single hour with AM/PM (now supported!)
+        ("B5", "=TIMEVALUE(\"2 PM\")"),
+        ("B6", "=TIMEVALUE(\"2 AM\")"),
+        // Date-time formats (extract time only)
+        ("C1", "=TIMEVALUE(\"2023-01-01 14:30:00\")"),
+        ("C2", "=TIMEVALUE(\"2023-01-01T14:30:00\")"),
+        // Whitespace handling
+        ("D1", "=TIMEVALUE(\" 14:30 \")"),
+    ]);
+
+    // Basic formats
+    assert_eq!(model._get_text("A1"), *TIME_14_30);
+    assert_eq!(model._get_text("A2"), *TIME_14_30_45);
+    assert_eq!(model._get_text("A3"), *MIDNIGHT);
+
+    // AM/PM formats
+    assert_eq!(model._get_text("B1"), *TIME_14_30); // 2:30 PM = 14:30
+    assert_eq!(model._get_text("B2"), *TIME_2_30_AM); // 2:30 AM
+    assert_eq!(model._get_text("B3"), *NOON); // 12:00 PM = noon
+    assert_eq!(model._get_text("B4"), *MIDNIGHT); // 12:00 AM = midnight
+
+    // Single hour AM/PM formats (now supported!)
+    assert_eq!(model._get_text("B5"), *TIME_2_PM); // 2 PM = 14:00
+    assert_eq!(model._get_text("B6"), *TIME_2_AM); // 2 AM = 02:00
+
+    // Date-time formats
+    assert_eq!(model._get_text("C1"), *TIME_14_30);
+    assert_eq!(model._get_text("C2"), *TIME_14_30);
+
+    // Whitespace
+    assert_eq!(model._get_text("D1"), *TIME_14_30);
+}
+
+#[test]
+fn test_timevalue_function_errors() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIMEVALUE()"),                 // Wrong arg count
+        ("A2", "=TIMEVALUE(\"14:30\", \"x\")"), // Wrong arg count
+        ("B1", "=TIMEVALUE(\"invalid\")"),      // Invalid format
+        ("B2", "=TIMEVALUE(\"25:00\")"),        // Invalid hour
+        ("B3", "=TIMEVALUE(\"14:70\")"),        // Invalid minute
+        ("B4", "=TIMEVALUE(\"\")"),             // Empty string
+        ("B5", "=TIMEVALUE(\"2PM\")"),          // Missing space (still unsupported)
+    ]);
+
+    // Wrong argument count should return #ERROR!
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+
+    // Invalid formats should return #VALUE!
+    assert_eq!(model._get_text("B1"), *"#VALUE!");
+    assert_eq!(model._get_text("B2"), *"#VALUE!");
+    assert_eq!(model._get_text("B3"), *"#VALUE!");
+    assert_eq!(model._get_text("B4"), *"#VALUE!");
+    assert_eq!(model._get_text("B5"), *"#VALUE!"); // "2PM" no space - not supported
+}
+
+#[test]
+fn test_time_component_extraction_comprehensive() {
+    // Test component extraction using helper function for consistency
+
+    // Test basic time values
+    let test_cases = [
+        (MIDNIGHT, ("0", "0", "0")),         // 00:00:00
+        (NOON, ("12", "0", "0")),            // 12:00:00
+        (TIME_14_30, ("14", "30", "0")),     // 14:30:00
+        (TIME_23_59_59, ("23", "59", "59")), // 23:59:59
+    ];
+
+    for (time_value, expected) in test_cases {
+        let (hour, minute, second) = test_component_extraction(time_value);
+        assert_eq!(hour, expected.0, "Hour mismatch for {time_value}");
+        assert_eq!(minute, expected.1, "Minute mismatch for {time_value}");
+        assert_eq!(second, expected.2, "Second mismatch for {time_value}");
+    }
+
+    // Test multiple days (extract from fractional part)
+    let (hour, minute, second) = test_component_extraction("1.5"); // Day 2, 12:00
+    assert_eq!(
+        (hour, minute, second),
+        ("12".to_string(), "0".to_string(), "0".to_string())
+    );
+
+    let (hour, minute, second) = test_component_extraction("100.604166667"); // Day 101, 14:30
+    assert_eq!(
+        (hour, minute, second),
+        ("14".to_string(), "30".to_string(), "0".to_string())
+    );
+
+    // Test precision at boundaries
+    let (hour, _, _) = test_component_extraction("0.041666666"); // Just under 1:00 AM
+    assert_eq!(hour, "0");
+
+    let (hour, _, _) = test_component_extraction("0.041666667"); // Exactly 1:00 AM
+    assert_eq!(hour, "1");
+
+    let (hour, _, _) = test_component_extraction("0.041666668"); // Just over 1:00 AM
+    assert_eq!(hour, "1");
+
+    // Test very large day values
+    let (hour, minute, second) = test_component_extraction("1000000.25"); // Million days + 6 hours
+    assert_eq!(
+        (hour, minute, second),
+        ("6".to_string(), "0".to_string(), "0".to_string())
+    );
+}
+
+#[test]
+fn test_time_component_function_errors() {
+    let model = test_time_expressions(&[
+        // Wrong argument counts
+        ("A1", "=HOUR()"),       // No arguments
+        ("A2", "=MINUTE()"),     // No arguments
+        ("A3", "=SECOND()"),     // No arguments
+        ("A4", "=HOUR(1, 2)"),   // Too many arguments
+        ("A5", "=MINUTE(1, 2)"), // Too many arguments
+        ("A6", "=SECOND(1, 2)"), // Too many arguments
+        // Negative values should return #NUM!
+        ("B1", "=HOUR(-0.5)"),        // Negative value
+        ("B2", "=MINUTE(-1)"),        // Negative value
+        ("B3", "=SECOND(-1)"),        // Negative value
+        ("B4", "=HOUR(-0.000001)"),   // Slightly negative
+        ("B5", "=MINUTE(-0.000001)"), // Slightly negative
+        ("B6", "=SECOND(-0.000001)"), // Slightly negative
+    ]);
+
+    // Wrong argument count should return #ERROR!
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+
+    // Negative values should return #NUM!
+    assert_eq!(model._get_text("B1"), *"#NUM!");
+    assert_eq!(model._get_text("B2"), *"#NUM!");
+    assert_eq!(model._get_text("B3"), *"#NUM!");
+    assert_eq!(model._get_text("B4"), *"#NUM!");
+    assert_eq!(model._get_text("B5"), *"#NUM!");
+    assert_eq!(model._get_text("B6"), *"#NUM!");
+}
+
+#[test]
+fn test_time_functions_integration() {
+    // Test how TIME, TIMEVALUE and component extraction functions work together
+    let model = test_time_expressions(&[
+        // Create times with both functions
+        ("A1", "=TIME(14,30,45)"),
+        ("A2", "=TIMEVALUE(\"14:30:45\")"),
+        // Extract components from TIME function results
+        ("B1", "=HOUR(A1)"),
+        ("B2", "=MINUTE(A1)"),
+        ("B3", "=SECOND(A1)"),
+        // Extract components from TIMEVALUE function results
+        ("C1", "=HOUR(A2)"),
+        ("C2", "=MINUTE(A2)"),
+        ("C3", "=SECOND(A2)"),
+        // Test additional TIME variations
+        ("D1", "=TIME(14,0,0)"), // 14:00:00
+        ("E1", "=HOUR(D1)"),     // Extract hour from 14:00:00
+        ("E2", "=MINUTE(D1)"),   // Extract minute from 14:00:00
+        ("E3", "=SECOND(D1)"),   // Extract second from 14:00:00
+    ]);
+
+    // TIME and TIMEVALUE should produce equivalent results
+    assert_eq!(model._get_text("A1"), model._get_text("A2"));
+
+    // Extracting components should work consistently
+    assert_eq!(model._get_text("B1"), *"14");
+    assert_eq!(model._get_text("B2"), *"30");
+    assert_eq!(model._get_text("B3"), *"45");
+    assert_eq!(model._get_text("C1"), *"14");
+    assert_eq!(model._get_text("C2"), *"30");
+    assert_eq!(model._get_text("C3"), *"45");
+
+    // Components from TIME(14,0,0)
+    assert_eq!(model._get_text("E1"), *"14");
+    assert_eq!(model._get_text("E2"), *"0");
+    assert_eq!(model._get_text("E3"), *"0");
+}
+
+#[test]
+fn test_time_function_extreme_values() {
+    // Test missing edge cases: very large fractional inputs
+    let model = test_time_expressions(&[
+        // Extremely large fractional values to TIME function
+        ("A1", "=TIME(999999.9, 999999.9, 999999.9)"), // Very large fractional inputs
+        ("A2", "=TIME(1e6, 1e6, 1e6)"),                // Scientific notation inputs
+        ("A3", "=TIME(0.000001, 0.000001, 0.000001)"), // Very small fractional inputs
+        // Large day values for component extraction (stress test)
+        ("B1", "=HOUR(999999.999)"), // Almost a million days
+        ("B2", "=MINUTE(999999.999)"),
+        ("B3", "=SECOND(999999.999)"),
+        // Edge case: exactly 1.0 (should be midnight of next day)
+        ("C1", "=HOUR(1.0)"),
+        ("C2", "=MINUTE(1.0)"),
+        ("C3", "=SECOND(1.0)"),
+        // Very high precision values
+        ("D1", "=HOUR(0.999999999999)"), // Almost exactly 24:00:00
+        ("D2", "=MINUTE(0.999999999999)"),
+        ("D3", "=SECOND(0.999999999999)"),
+    ]);
+
+    // Large fractional inputs should be floored and normalized
+    let result_a1 = model._get_text("A1").parse::<f64>().unwrap();
+    assert!(
+        (0.0..1.0).contains(&result_a1),
+        "Result should be valid time fraction"
+    );
+
+    // Component extraction should work with very large values
+    let hour_b1 = model._get_text("B1").parse::<i32>().unwrap();
+    assert!((0..=23).contains(&hour_b1), "Hour should be 0-23");
+
+    // Exactly 1.0 should be midnight (start of next day)
+    assert_eq!(model._get_text("C1"), *"0");
+    assert_eq!(model._get_text("C2"), *"0");
+    assert_eq!(model._get_text("C3"), *"0");
+
+    // Very high precision should still extract valid components
+    let hour_d1 = model._get_text("D1").parse::<i32>().unwrap();
+    assert!((0..=23).contains(&hour_d1), "Hour should be 0-23");
+}
+
+#[test]
+fn test_timevalue_malformed_but_parseable() {
+    // Test missing edge case: malformed but potentially parseable strings
+    let model = test_time_expressions(&[
+        // Test various malformed but potentially parseable time strings
+        ("A1", "=TIMEVALUE(\"14:30:00.123\")"), // Milliseconds (might be truncated)
+        ("A2", "=TIMEVALUE(\"14:30:00.999\")"), // High precision milliseconds
+        ("A3", "=TIMEVALUE(\"02:30:00\")"),     // Leading zero hours
+        ("A4", "=TIMEVALUE(\"2:05:00\")"),      // Single digit hour, zero-padded minute
+        // Boundary cases for AM/PM parsing
+        ("B1", "=TIMEVALUE(\"11:59:59 PM\")"), // Just before midnight
+        ("B2", "=TIMEVALUE(\"12:00:01 AM\")"), // Just after midnight
+        ("B3", "=TIMEVALUE(\"12:00:01 PM\")"), // Just after noon
+        ("B4", "=TIMEVALUE(\"11:59:59 AM\")"), // Just before noon
+        // Test various date-time combinations
+        ("C1", "=TIMEVALUE(\"2023-12-31T23:59:59\")"), // ISO format at year end
+        ("C2", "=TIMEVALUE(\"2023-01-01 00:00:01\")"), // New year, just after midnight
+        // Test potential edge cases that might still be parseable
+        ("D1", "=TIMEVALUE(\"24:00:00\")"), // Should error (invalid hour)
+        ("D2", "=TIMEVALUE(\"23:60:00\")"), // Should error (invalid minute)
+        ("D3", "=TIMEVALUE(\"23:59:60\")"), // Should error (invalid second)
+    ]);
+
+    // Milliseconds are not supported, should return a #VALUE! error like Excel
+    assert_eq!(model._get_text("A1"), *"#VALUE!");
+    assert_eq!(model._get_text("A2"), *"#VALUE!");
+
+    // Leading zeros should work fine
+    assert_eq!(model._get_text("A3"), *TIME_2_30_AM); // 02:30:00 should parse as 2:30:00
+
+    // AM/PM boundary cases should work
+    let result_b1 = model._get_text("B1").parse::<f64>().unwrap();
+    assert!(
+        result_b1 > 0.99 && result_b1 < 1.0,
+        "11:59:59 PM should be very close to 1.0"
+    );
+
+    let result_b2 = model._get_text("B2").parse::<f64>().unwrap();
+    assert!(
+        result_b2 > 0.0 && result_b2 < 0.01,
+        "12:00:01 AM should be very close to 0.0"
+    );
+
+    // ISO 8601 format with "T" separator should be parsed correctly
+    assert_eq!(model._get_text("C1"), *TIME_23_59_59); // 23:59:59 → almost midnight
+    assert_eq!(model._get_text("C2"), *TIME_00_00_01); // 00:00:01 → one second past midnight
+
+    // Time parser normalizes edge cases to midnight (Excel compatibility)
+    assert_eq!(model._get_text("D1"), *"0"); // 24:00:00 = midnight of next day
+    assert_eq!(model._get_text("D2"), *"0"); // 23:60:00 normalizes to 24:00:00 = midnight
+    assert_eq!(model._get_text("D3"), *"0"); // 23:59:60 normalizes to 24:00:00 = midnight
+}
+
+#[test]
+fn test_performance_stress_with_extreme_values() {
+    // Test performance/stress cases with extreme values
+    let model = test_time_expressions(&[
+        // Very large numbers that should still work
+        ("A1", "=TIME(2147483647, 0, 0)"), // Max i32 hours
+        ("A2", "=TIME(0, 2147483647, 0)"), // Max i32 minutes
+        ("A3", "=TIME(0, 0, 2147483647)"), // Max i32 seconds
+        // Component extraction with extreme day values
+        ("B1", "=HOUR(1e15)"), // Very large day number
+        ("B2", "=MINUTE(1e15)"),
+        ("B3", "=SECOND(1e15)"),
+        // Edge of floating point precision
+        ("C1", "=HOUR(1.7976931348623157e+308)"), // Near max f64
+        ("C2", "=HOUR(2.2250738585072014e-308)"), // Near min positive f64
+        // Multiple TIME function calls with large values
+        ("D1", "=TIME(1000000, 1000000, 1000000)"), // Large normalized values
+        ("D2", "=HOUR(D1)"),                        // Extract from large TIME result
+        ("D3", "=MINUTE(D1)"),
+        ("D4", "=SECOND(D1)"),
+    ]);
+
+    // All results should be valid (not errors) even with extreme inputs
+    for cell in ["A1", "A2", "A3", "B1", "B2", "B3", "D1", "D2", "D3", "D4"] {
+        let result = model._get_text(cell);
+        assert!(
+            result != *"#ERROR!" && result != *"#NUM!" && result != *"#VALUE!",
+            "Cell {cell} should not error with extreme values: {result}",
+        );
+    }
+
+    // Results should be mathematically valid
+    let hour_b1 = model._get_text("B1").parse::<i32>().unwrap();
+    let minute_b2 = model._get_text("B2").parse::<i32>().unwrap();
+    let second_b3 = model._get_text("B3").parse::<i32>().unwrap();
+
+    assert!((0..=23).contains(&hour_b1));
+    assert!((0..=59).contains(&minute_b2));
+    assert!((0..=59).contains(&second_b3));
+
+    // TIME function results should be valid time fractions
+    let time_d1 = model._get_text("D1").parse::<f64>().unwrap();
+    assert!(
+        (0.0..1.0).contains(&time_d1),
+        "TIME result should be valid fraction"
+    );
+}

base/src/test/test_issue_483.rs

@@ -0,0 +1,13 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn issue_155() {
+    let mut model = new_empty_model();
+    model._set("A1", "123");
+    model._set("D2", "=-(A1^1.22)");
+    model.evaluate();
+
+    assert_eq!(model._get_formula("D2"), "=-(A1^1.22)".to_string());
+}

base/src/test/test_mod_quotient.rs

@@ -0,0 +1,22 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=MOD(5,2)");
+    model._set("A2", "=MOD()");
+    model._set("A3", "=MOD(5, 2, 1)");
+    model._set("A4", "=QUOTIENT(5, 2)");
+    model._set("A5", "=QUOTIENT()");
+    model._set("A6", "=QUOTIENT(5, 2, 1)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"1");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"2");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_mround_trunc_int

@@ -0,0 +1,40 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=MROUND()");
+    model._set("A2", "=MROUND(10)");
+    model._set("A3", "=MROUND(10, 3)");
+    model._set("A4", "=MROUND(10, 3, 1)");
+
+    model._set("A5", "=TRUNC()");
+    model._set("A6", "=TRUNC(10)");
+    model._set("A7", "=TRUNC(10.22, 1)");
+    model._set("A8", "=TRUNC(10, 3, 1)");
+
+    model._set("A9", "=INT()");
+    model._set("A10", "=INT(10.22)");
+    model._set("A11", "=INT(10.22, 1)");
+    model._set("A12", "=INT(10.22, 1, 2)");
+
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"9");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"10.2");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A9"), *"#ERROR!");
+    assert_eq!(model._get_text("A10"), *"10");
+    assert_eq!(model._get_text("A11"), *"#ERROR!");
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+}

base/src/test/test_networkdays.rs

@@ -0,0 +1,347 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+// Test data: Jan 1-10, 2023 week
+const JAN_1_2023: i32 = 44927; // Sunday
+const JAN_2_2023: i32 = 44928; // Monday
+const JAN_6_2023: i32 = 44932; // Friday
+const JAN_9_2023: i32 = 44935; // Monday
+const JAN_10_2023: i32 = 44936; // Tuesday
+
+#[test]
+fn networkdays_calculates_weekdays_excluding_weekends() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Should count 7 weekdays in 10-day span"
+    );
+}
+
+#[test]
+fn networkdays_handles_reverse_date_order() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_10_2023},{JAN_1_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "-7",
+        "Reversed dates should return negative count"
+    );
+}
+
+#[test]
+fn networkdays_excludes_holidays_from_weekdays() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},{JAN_9_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "6",
+        "Should exclude Monday holiday from 7 weekdays"
+    );
+}
+
+#[test]
+fn networkdays_handles_same_start_end_date() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_9_2023},{JAN_9_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "1",
+        "Same weekday date should count as 1 workday"
+    );
+}
+
+#[test]
+fn networkdays_accepts_holiday_ranges() {
+    let mut model = new_empty_model();
+
+    model._set("B1", &JAN_2_2023.to_string());
+    model._set("B2", &JAN_6_2023.to_string());
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1:B2)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "5",
+        "Should exclude 2 holidays from 7 weekdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_uses_standard_weekend_by_default() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Default should be Saturday-Sunday weekend"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_numeric_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    // Pattern 2 = Sunday-Monday weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},2)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "6",
+        "Sunday-Monday weekend should give 6 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_single_day_weekends() {
+    let mut model = new_empty_model();
+
+    // Pattern 11 = Sunday only weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},11)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "8",
+        "Sunday-only weekend should give 8 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_string_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    // "0000110" = Friday-Saturday weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000110\")"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "8",
+        "Friday-Saturday weekend should give 8 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_no_weekends_counts_all_days() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000000\")"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "10",
+        "No weekends should count all 10 days"
+    );
+}
+
+#[test]
+fn networkdays_intl_combines_custom_weekends_with_holidays() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000110\",{JAN_9_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Should exclude both weekend and holiday"
+    );
+}
+
+#[test]
+fn networkdays_validates_argument_count() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS()");
+    model._set("A2", "=NETWORKDAYS(1,2,3,4)");
+    model._set("A3", "=NETWORKDAYS.INTL()");
+    model._set("A4", "=NETWORKDAYS.INTL(1,2,3,4,5)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#ERROR!");
+    assert_eq!(model._get_text("A2"), "#ERROR!");
+    assert_eq!(model._get_text("A3"), "#ERROR!");
+    assert_eq!(model._get_text("A4"), "#ERROR!");
+}
+
+#[test]
+fn networkdays_rejects_invalid_dates() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(-1,100)");
+    model._set("A2", "=NETWORKDAYS(1,3000000)");
+    model._set("A3", "=NETWORKDAYS(\"text\",100)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#NUM!");
+    assert_eq!(model._get_text("A2"), "#NUM!");
+    assert_eq!(model._get_text("A3"), "#VALUE!");
+}
+
+#[test]
+fn networkdays_intl_rejects_invalid_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS.INTL(1,10,99)");
+    model._set("A2", "=NETWORKDAYS.INTL(1,10,\"111110\")");
+    model._set("A3", "=NETWORKDAYS.INTL(1,10,\"11111000\")");
+    model._set("A4", "=NETWORKDAYS.INTL(1,10,\"1111102\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#NUM!");
+    assert_eq!(model._get_text("A2"), "#VALUE!");
+    assert_eq!(model._get_text("A3"), "#VALUE!");
+    assert_eq!(model._get_text("A4"), "#VALUE!");
+}
+
+#[test]
+fn networkdays_rejects_invalid_holidays() {
+    let mut model = new_empty_model();
+
+    model._set("B1", "invalid");
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1)"),
+    );
+    model._set(
+        "A2",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},-1)"),
+    );
+
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "#VALUE!",
+        "Should reject non-numeric holidays"
+    );
+    assert_eq!(
+        model._get_text("A2"),
+        "#NUM!",
+        "Should reject out-of-range holidays"
+    );
+}
+
+#[test]
+fn networkdays_handles_weekend_only_periods() {
+    let mut model = new_empty_model();
+
+    let saturday = JAN_1_2023 - 1;
+    model._set("A1", &format!("=NETWORKDAYS({saturday},{JAN_1_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "0",
+        "Weekend-only period should count 0 workdays"
+    );
+}
+
+#[test]
+fn networkdays_ignores_holidays_outside_date_range() {
+    let mut model = new_empty_model();
+
+    let future_holiday = JAN_10_2023 + 100;
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},{future_holiday})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Out-of-range holidays should be ignored"
+    );
+}
+
+#[test]
+fn networkdays_handles_empty_holiday_ranges() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1:B3)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Empty holiday range should be treated as no holidays"
+    );
+}
+
+#[test]
+fn networkdays_handles_minimum_valid_dates() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(1,7)");
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "5",
+        "Should handle earliest Excel dates correctly"
+    );
+}
+
+#[test]
+fn networkdays_handles_large_date_ranges_efficiently() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(1,365)");
+    model.evaluate();
+
+    assert!(
+        !model._get_text("A1").starts_with('#'),
+        "Large ranges should not error"
+    );
+}

base/src/test/test_now.rs

@@ -0,0 +1,30 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{mock_time, test::util::new_empty_model};
+
+// 14:44 20 Mar 2023 Berlin
+const TIMESTAMP_2023: i64 = 1679319865208;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NOW(1)");
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "#ERROR!",
+        "NOW should not accept arguments"
+    );
+}
+
+#[test]
+fn returns_date_time() {
+    mock_time::set_mock_time(TIMESTAMP_2023);
+    let mut model = new_empty_model();
+    model._set("A1", "=NOW()");
+    model.evaluate();
+    let text = model._get_text("A1");
+    assert_eq!(text, *"20/03/2023 13:44:25");
+}

base/src/test/test_number_format.rs

@@ -8,6 +8,15 @@ fn test_simple_format() {
     assert_eq!(formatted.text, "2.3".to_string());
 }
 
+#[test]
+fn test_maximum_zeros() {
+    let formatted = format_number(1.0 / 3.0, "#,##0.0000000000000000000", "en");
+    assert_eq!(formatted.text, "0.3333333333333330000".to_string());
+
+    let formatted = format_number(1234.0 + 1.0 / 3.0, "#,##0.0000000000000000000", "en");
+    assert_eq!(formatted.text, "1,234.3333333333300000000".to_string());
+}
+
 #[test]
 #[ignore = "not yet implemented"]
 fn test_wrong_locale() {

base/src/test/test_sheet_names.rs

@@ -0,0 +1,16 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn sheet_number_name() {
+    let mut model = new_empty_model();
+    model.new_sheet();
+    model._set("A1", "7");
+    model._set("A2", "=Sheet2!C3");
+    model.evaluate();
+    model.rename_sheet("Sheet2", "2024").unwrap();
+    model.evaluate();
+    assert_eq!(model.workbook.get_worksheet_names(), ["Sheet1", "2024"]);
+    assert_eq!(model._get_text("A2"), "0");
+}

base/src/test/test_today.rs

@@ -33,7 +33,8 @@ fn now_basic_utc() {
     model.evaluate();
 
     assert_eq!(model._get_text("A1"), *"20/03/2023");
-    assert_eq!(model._get_text("A2"), *"45005.572511574");
+    // 45005.572511574
+    assert_eq!(model._get_text("A2"), *"20/03/2023 13:44:25");
 }
 
 #[test]
@@ -46,5 +47,5 @@ fn now_basic_europe_berlin() {
 
     assert_eq!(model._get_text("A1"), *"20/03/2023");
     // This is UTC + 1 hour: 45005.572511574 + 1/24
-    assert_eq!(model._get_text("A2"), *"45005.614178241");
+    assert_eq!(model._get_text("A2"), *"20/03/2023 14:44:25");
 }

base/src/test/test_trigonometric.rs

@@ -96,3 +96,14 @@ fn test_fn_tan_pi2() {
     // This is consistent with IEEE 754 but inconsistent with Excel
     assert_eq!(model._get_text("A1"), *"1.63312E+16");
 }
+
+#[test]
+fn test_trigonometric_identity() {
+    let mut model = new_empty_model();
+    model._set("A1", "=COTH(1)*CSCH(1)");
+    model._set("A2", "=COSH(1)/(SINH(1))^2");
+    model._set("A3", "=A1=A2");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A3"), *"TRUE");
+}

base/src/test/test_trigonometric_reciprocals.rs

@@ -0,0 +1,53 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=CSC()");
+    model._set("A2", "=SEC()");
+    model._set("A3", "=COT()");
+
+    model._set("A4", "=CSCH()");
+    model._set("A5", "=SECH()");
+    model._set("A6", "=COTH()");
+
+    model._set("A7", "=ACOT()");
+    model._set("A8", "=ACOTH()");
+
+    model._set("B1", "=CSC(1, 2)");
+    model._set("B2", "=SEC(1, 2)");
+    model._set("B3", "=COT(1, 2)");
+
+    model._set("B4", "=CSCH(1, 2)");
+    model._set("B5", "=SECH(1, 2)");
+    model._set("B6", "=COTH(1, 2)");
+
+    model._set("B7", "=ACOT(1, 2)");
+    model._set("B8", "=ACOTH(1, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B1"), *"#ERROR!");
+    assert_eq!(model._get_text("B2"), *"#ERROR!");
+    assert_eq!(model._get_text("B3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B4"), *"#ERROR!");
+    assert_eq!(model._get_text("B5"), *"#ERROR!");
+    assert_eq!(model._get_text("B6"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B7"), *"#ERROR!");
+    assert_eq!(model._get_text("B8"), *"#ERROR!");
+}

base/src/test/test_weekday_return_types.rs

@@ -0,0 +1,26 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_weekday_return_types_11_to_17() {
+    let mut model = new_empty_model();
+
+    // Test date: 44561 corresponds to a Friday (2021-12-31). We verify the
+    // numeric result for each custom week start defined by return_type 11-17.
+    model._set("A1", "=WEEKDAY(44561,11)"); // Monday start
+    model._set("A2", "=WEEKDAY(44561,12)"); // Tuesday start
+    model._set("A3", "=WEEKDAY(44561,13)"); // Wednesday start
+    model._set("A4", "=WEEKDAY(44561,14)"); // Thursday start
+    model._set("A5", "=WEEKDAY(44561,15)"); // Friday start
+    model._set("A6", "=WEEKDAY(44561,16)"); // Saturday start
+    model._set("A7", "=WEEKDAY(44561,17)"); // Sunday start
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"5"); // Mon=1 .. Sun=7 ⇒ Fri=5
+    assert_eq!(model._get_text("A2"), *"4"); // Tue start ⇒ Fri=4
+    assert_eq!(model._get_text("A3"), *"3"); // Wed start ⇒ Fri=3
+    assert_eq!(model._get_text("A4"), *"2"); // Thu start ⇒ Fri=2
+    assert_eq!(model._get_text("A5"), *"1"); // Fri start ⇒ Fri=1
+    assert_eq!(model._get_text("A6"), *"7"); // Sat start ⇒ Fri=7
+    assert_eq!(model._get_text("A7"), *"6"); // Sun start ⇒ Fri=6
+}

base/src/test/test_weeknum_return_types.rs

@@ -0,0 +1,31 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_weeknum_return_types_11_to_17_and_21() {
+    let mut model = new_empty_model();
+
+    // Date 44561 -> 2021-12-31 (Friday). Previously verified as week 53 (Sunday/Monday start).
+    // We verify that custom week-start codes 11-17 all map to week 53 and ISO variant (21) maps to 52.
+    let formulas = [
+        ("A1", "=WEEKNUM(44561,11)"),
+        ("A2", "=WEEKNUM(44561,12)"),
+        ("A3", "=WEEKNUM(44561,13)"),
+        ("A4", "=WEEKNUM(44561,14)"),
+        ("A5", "=WEEKNUM(44561,15)"),
+        ("A6", "=WEEKNUM(44561,16)"),
+        ("A7", "=WEEKNUM(44561,17)"),
+        ("A8", "=WEEKNUM(44561,21)"), // ISO week numbering
+    ];
+    for (cell, formula) in formulas {
+        model._set(cell, formula);
+    }
+
+    model.evaluate();
+
+    // All 11-17 variations should yield 53
+    for cell in ["A1", "A2", "A3", "A4", "A5", "A6", "A7"] {
+        assert_eq!(model._get_text(cell), *"53", "{cell} should be 53");
+    }
+    // ISO week (return_type 21)
+    assert_eq!(model._get_text("A8"), *"52");
+}

base/src/test/test_yearfrac_basis.rs

@@ -0,0 +1,60 @@
+#![allow(clippy::panic)]
+use crate::{cell::CellValue, test::util::new_empty_model};
+
+#[test]
+fn test_yearfrac_basis_2_actual_360() {
+    let mut model = new_empty_model();
+
+    // Non-leap span of exactly 360 days should result in 1.0
+    model._set("A1", "=YEARFRAC(44561,44921,2)");
+
+    // Leap-year span of 366 days: Jan 1 2020 → Jan 1 2021
+    model._set("A2", "=YEARFRAC(43831,44197,2)");
+
+    // Reverse order should yield negative value
+    model._set("A3", "=YEARFRAC(44921,44561,2)");
+
+    model.evaluate();
+
+    // 360/360
+    assert_eq!(model._get_text("A1"), *"1");
+
+    // 366/360 ≈ 1.0166666667 (tolerance 1e-10)
+    if let Ok(CellValue::Number(v)) = model.get_cell_value_by_ref("Sheet1!A2") {
+        assert!((v - 1.016_666_666_7).abs() < 1e-10);
+    } else {
+        panic!("Expected numeric value in A2");
+    }
+
+    // always positive A1
+    assert_eq!(model._get_text("A3"), *"1");
+}
+
+#[test]
+fn test_yearfrac_basis_3_actual_365() {
+    let mut model = new_empty_model();
+
+    // Non-leap span of exactly 365 days should result in 1.0
+    model._set("B1", "=YEARFRAC(44561,44926,3)");
+
+    // Leap-year span of 366 days
+    model._set("B2", "=YEARFRAC(43831,44197,3)");
+
+    // Same date should be 0
+    model._set("B3", "=YEARFRAC(44561,44561,3)");
+
+    model.evaluate();
+
+    // 365/365
+    assert_eq!(model._get_text("B1"), *"1");
+
+    // 366/365 ≈ 1.002739726 (tolerance 1e-10)
+    if let Ok(CellValue::Number(v)) = model.get_cell_value_by_ref("Sheet1!B2") {
+        assert!((v - 1.002_739_726).abs() < 1e-10);
+    } else {
+        panic!("Expected numeric value in B2");
+    }
+
+    // Same date
+    assert_eq!(model._get_text("B3"), *"0");
+}

base/src/test/user_model/test_clear_cells.rs

@@ -89,3 +89,67 @@ fn clear_all_empty_cell() {
     model.undo().unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 1, 1), Ok("".to_string()));
 }
+
+#[test]
+fn issue_454() {
+    let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
+    model
+        .set_user_input(
+            0,
+            1,
+            1,
+            "Le presbytère n'a rien perdu de son charme, ni le jardin de son éclat.",
+        )
+        .unwrap();
+    model.set_user_input(0, 1, 2, "=ISTEXT(A1)").unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("TRUE".to_string())
+    );
+    model
+        .range_clear_contents(&Area {
+            sheet: 0,
+            row: 1,
+            column: 1,
+            width: 1,
+            height: 1,
+        })
+        .unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("FALSE".to_string())
+    );
+    model.undo().unwrap();
+}
+
+#[test]
+fn issue_454b() {
+    let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
+    model
+        .set_user_input(
+            0,
+            1,
+            1,
+            "Le presbytère n'a rien perdu de son charme, ni le jardin de son éclat.",
+        )
+        .unwrap();
+    model.set_user_input(0, 1, 2, "=ISTEXT(A1)").unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("TRUE".to_string())
+    );
+    model
+        .range_clear_all(&Area {
+            sheet: 0,
+            row: 1,
+            column: 1,
+            width: 1,
+            height: 1,
+        })
+        .unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("FALSE".to_string())
+    );
+    model.undo().unwrap();
+}

base/src/test/user_model/test_defined_names.rs

@@ -254,19 +254,19 @@ fn invalid_names() {
     // spaces
     assert_eq!(
         model.new_defined_name("A real", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 
     // Starts with number
     assert_eq!(
         model.new_defined_name("2real", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 
     // Updating also fails
     assert_eq!(
         model.update_defined_name("MyName", None, "My Name", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 }
 
@@ -284,13 +284,13 @@ fn already_existing() {
     // Can't create a new name with the same name
     assert_eq!(
         model.new_defined_name("MyName", None, "Sheet1!$A$2"),
-        Err("Defined name already exists".to_string())
+        Err("Name: Defined name already exists".to_string())
     );
 
     // Can't update one into an existing
     assert_eq!(
         model.update_defined_name("Another", None, "MyName", None, "Sheet1!$A$1"),
-        Err("Defined name already exists".to_string())
+        Err("Name: Defined name already exists".to_string())
     );
 }
 
@@ -304,17 +304,17 @@ fn invalid_sheet() {
 
     assert_eq!(
         model.new_defined_name("Mything", Some(2), "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("Scope: Invalid sheet index".to_string())
     );
 
     assert_eq!(
         model.update_defined_name("MyName", None, "MyName", Some(2), "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("Scope: Invalid sheet index".to_string())
     );
 
     assert_eq!(
         model.update_defined_name("MyName", Some(9), "YourName", None, "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("General: Failed to get old name".to_string())
     );
 }
 
@@ -322,7 +322,7 @@ fn invalid_sheet() {
 fn invalid_formula() {
     let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
     model.set_user_input(0, 1, 1, "Hello").unwrap();
-    model.new_defined_name("MyName", None, "A1").unwrap();
+    assert!(model.new_defined_name("MyName", None, "A1").is_err());
 
     model.set_user_input(0, 1, 2, "=MyName").unwrap();
 

base/src/types.rs

@@ -445,11 +445,13 @@ impl Default for Fill {
 
 #[derive(Serialize, Deserialize, Encode, Decode, Debug, PartialEq, Eq, Clone)]
 #[serde(rename_all = "lowercase")]
+#[derive(Default)]
 pub enum HorizontalAlignment {
     Center,
     CenterContinuous,
     Distributed,
     Fill,
+    #[default]
     General,
     Justify,
     Left,
@@ -457,11 +459,6 @@ pub enum HorizontalAlignment {
 }
 
 // Note that alignment in "General" depends on type
-impl Default for HorizontalAlignment {
-    fn default() -> Self {
-        Self::General
-    }
-}
 
 impl HorizontalAlignment {
     fn is_default(&self) -> bool {
@@ -487,7 +484,9 @@ impl Display for HorizontalAlignment {
 
 #[derive(Serialize, Deserialize, Encode, Decode, Debug, PartialEq, Eq, Clone)]
 #[serde(rename_all = "lowercase")]
+#[derive(Default)]
 pub enum VerticalAlignment {
+    #[default]
     Bottom,
     Center,
     Distributed,
@@ -501,12 +500,6 @@ impl VerticalAlignment {
     }
 }
 
-impl Default for VerticalAlignment {
-    fn default() -> Self {
-        Self::Bottom
-    }
-}
-
 impl Display for VerticalAlignment {
     fn fmt(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {

base/src/units.rs

@@ -329,6 +329,7 @@ impl Model {
             Function::Tbillyield => self.units_fn_percentage_2(args, cell),
             Function::Date => self.units_fn_dates(args, cell),
             Function::Today => self.units_fn_dates(args, cell),
+            Function::Now => self.units_fn_date_times(args, cell),
             _ => None,
         }
     }
@@ -375,4 +376,8 @@ impl Model {
         // TODO: update locale and use it here
         Some(Units::Date("dd/mm/yyyy".to_string()))
     }
+
+    fn units_fn_date_times(&self, _args: &[Node], _cell: &CellReferenceIndex) -> Option<Units> {
+        Some(Units::Date("dd/mm/yyyy hh:mm:ss".to_string()))
+    }
 }

base/src/user_model/common.rs

@@ -627,6 +627,7 @@ impl UserModel {
             }
         }
         self.push_diff_list(diff_list);
+        self.evaluate_if_not_paused();
         Ok(())
     }
 
@@ -656,6 +657,7 @@ impl UserModel {
             }
         }
         self.push_diff_list(diff_list);
+        self.evaluate_if_not_paused();
         Ok(())
     }
 
@@ -1999,7 +2001,10 @@ impl UserModel {
         new_scope: Option<u32>,
         new_formula: &str,
     ) -> Result<(), String> {
-        let old_formula = self.model.get_defined_name_formula(name, scope)?;
+        let old_formula = self
+            .model
+            .get_defined_name_formula(name, scope)
+            .map_err(|_| "General: Failed to get old name")?;
         let diff_list = vec![Diff::UpdateDefinedName {
             name: name.to_string(),
             scope,
@@ -2015,6 +2020,16 @@ impl UserModel {
         Ok(())
     }
 
+    /// validates a new defined name
+    pub fn is_valid_defined_name(
+        &self,
+        name: &str,
+        scope: Option<u32>,
+        formula: &str,
+    ) -> Result<Option<u32>, String> {
+        self.model.is_valid_defined_name(name, scope, formula)
+    }
+
     // **** Private methods ****** //
 
     pub(crate) fn push_diff_list(&mut self, diff_list: DiffList) {

bindings/nodejs/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 edition = "2021"
 name = "ironcalc_nodejs"
-version = "0.5.0"
+version = "0.6.0"
 
 [lib]
 crate-type = ["cdylib"]
@@ -10,7 +10,7 @@ crate-type = ["cdylib"]
 # Default enable napi4 feature, see https://nodejs.org/api/n-api.html#node-api-version-matrix
 napi = { version = "2.12.2", default-features = false, features = ["napi4", "serde-json"] }
 napi-derive = "2.12.2"
-ironcalc = { path = "../../xlsx", version = "0.5.0" }
+ironcalc = { path = "../../xlsx", version = "0.6.0" }
 serde = { version = "1.0", features = ["derive"] }
 
 [build-dependencies]

bindings/python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyroncalc"
-version = "0.5.7"
+version = "0.6.0"
 edition = "2021"
 
 
@@ -12,7 +12,7 @@ crate-type = ["cdylib"]
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-xlsx = { package= "ironcalc", path = "../../xlsx", version = "0.5.0" }
+xlsx = { package= "ironcalc", path = "../../xlsx", version = "0.6.0" }
 pyo3 = { version = "0.25", features = ["extension-module"] }
 bitcode = "0.6.3"
 

bindings/python/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "ironcalc"
-version = "0.5.7"
+version = "0.6.0"
 description = "Create, edit and evaluate Excel spreadsheets"
 requires-python = ">=3.10"
 keywords = [

bindings/wasm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "wasm"
-version = "0.5.0"
+version = "0.6.0"
 authors = ["Nicolas Hatcher <nicolas@theuniverse.today>"]
 description = "IronCalc Web bindings"
 license = "MIT/Apache-2.0"
@@ -14,7 +14,7 @@ crate-type = ["cdylib"]
 # Uses `../ironcalc/base` when used locally, and uses
 # the inicated version from crates.io when published.
 # https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#multiple-locations
-ironcalc_base = { path = "../../base", version = "0.5", features = ["use_regex_lite"] }
+ironcalc_base = { path = "../../base", version = "0.6", features = ["use_regex_lite"] }
 serde = { version = "1.0", features = ["derive"] }
 wasm-bindgen = "0.2.100"
 serde-wasm-bindgen = "0.4"

bindings/wasm/src/lib.rs

@@ -5,7 +5,11 @@ use wasm_bindgen::{
 };
 
 use ironcalc_base::{
-    expressions::{lexer::util::get_tokens as tokenizer, types::Area, utils::number_to_column},
+    expressions::{
+        lexer::util::get_tokens as tokenizer,
+        types::Area,
+        utils::{number_to_column, quote_name as quote_name_ic},
+    },
     types::{CellType, Style},
     worksheet::NavigationDirection,
     BorderArea, ClipboardData, UserModel as BaseModel,
@@ -31,6 +35,11 @@ pub fn column_name_from_number(column: i32) -> Result<String, JsError> {
     }
 }
 
+#[wasm_bindgen(js_name = "quoteName")]
+pub fn quote_name(name: &str) -> String {
+    quote_name_ic(name)
+}
+
 #[derive(Serialize)]
 struct DefinedName {
     name: String,
@@ -766,4 +775,17 @@ impl Model {
             .get_first_non_empty_in_row_after_column(sheet, row, column)
             .map_err(to_js_error)
     }
+
+    #[wasm_bindgen(js_name = "isValidDefinedName")]
+    pub fn is_valid_defined_name(
+        &self,
+        name: &str,
+        scope: Option<u32>,
+        formula: &str,
+    ) -> Result<(), JsError> {
+        match self.model.is_valid_defined_name(name, scope, formula) {
+            Ok(_) => Ok(()),
+            Err(e) => Err(to_js_error(e.to_string())),
+        }
+    }
 }

docker-compose.yml

@@ -0,0 +1,14 @@
+services:
+  server:
+    image: ghcr.io/ironcalc/ironcalc-server:0.6.0
+    build:
+      context: .
+      target: server-runtime
+
+  caddy:
+    image: ghcr.io/ironcalc/ironcalc-caddy:0.6.0
+    build:
+      context: .
+      target: caddy-runtime
+    ports:
+      - "2080:2080"

docs/package.json

@@ -6,7 +6,7 @@
   },
   "devDependencies": {
     "markdown-it-mathjax3": "^4.3.2",
-    "vitepress": "^v2.0.0-alpha.8",
+    "vitepress": "^v2.0.0-alpha.12",
     "vue": "^3.5.17"
   }
 }

docs/src/.vitepress/config.mts

@@ -2036,6 +2036,10 @@ export default defineConfig({
             text: "How to contribute",
             link: "/contributing/how-to-contribute",
           },
+          {
+            text: "Function documentation guide",
+            link: "/contributing/function-documentation-guide",
+          },
         ],
       },
     ],

docs/src/contributing/function-documentation-guide.md

@@ -0,0 +1,389 @@
+---
+layout: doc
+outline: deep
+lang: en-US
+---
+
+# Function Documentation Guide
+
+This guide explains how to document IronCalc functions following our established format and style conventions.
+
+## File Structure
+
+Function documentation files should be placed in the appropriate category directory under `src/functions/`. For example:
+
+- Financial functions: `src/functions/financial/function-name.md`
+- Text functions: `src/functions/text/function-name.md`
+- Logical functions: `src/functions/logical/function-name.md`
+
+## Required Frontmatter
+
+Every function documentation file must start with this frontmatter:
+
+```yaml
+---
+layout: doc
+outline: deep
+lang: en-US
+---
+```
+
+## Document Structure
+
+A complete function documentation should include the following sections in order:
+
+### 1. Title
+
+The title should be the function name followed by the word "function":
+
+```markdown
+# FV function
+```
+
+The function name should be written in uppercase when mentioned in the documentation.
+
+### 2. Draft Warning (Optional)
+
+If the function hasn't been implemented, include this warning box:
+
+```markdown
+::: warning
+**Note:** This draft page is under construction 🚧
+:::
+```
+
+If the function has been implemented but not documented, include this warning box:
+
+```markdown
+::: warning
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
+:::
+```
+
+### 3. Overview
+
+Provide a brief, clear description of what the function does. If the function name is an acronym, expand it using underlined text:
+
+```markdown
+## Overview
+
+FV (<u>F</u>uture <u>V</u>alue) is a function of the Financial category that can be used to predict the future value of an investment or asset based on its present value.
+```
+
+Include:
+
+- Category (Financial, Text, Logical, etc.)
+- Primary purpose
+- Key use cases (if helpful)
+
+### 4. Usage
+
+This section contains multiple subsections:
+
+#### 4.1 Syntax
+
+Format the function syntax with color-coded argument types. Use the following color scheme:
+
+- **Numbers**: `#2F80ED` (blue)
+- **Booleans**: `#27AE60` (green)
+- **Text/Strings**: `#2F80ED` (orange)
+- **Arrays/Ranges**: `#EB5757` (red)
+
+**Format:**
+
+```markdown
+### Syntax
+
+**FUNCTION_NAME(<span title="Type" style="color:#HEXCODE">arg1</span>, <span title="Type" style="color:#HEXCODE">arg2</span>=default, ...) => <span title="ReturnType" style="color:#HEXCODE">return_value</span>**
+```
+
+**Example:**
+
+**FV(<span title="Number" style="color:#2F80ED">rate</span>, <span title="Number" style="color:#2F80ED">nper</span>, <span title="Number" style="color:#2F80ED">pmt</span>, [<span title="Number" style="color:#2F80ED">pv</span>], [<span title="Boolean" style="color:#27AE60">type</span>]  => <span title="Number" style="color:#2F80ED">fv</span>**
+
+```markdown
+### Syntax
+
+**FV(<span title="Number" style="color:#2F80ED">rate</span>, <span title="Number" style="color:#2F80ED">nper</span>, <span title="Number" style="color:#2F80ED">pmt</span>, <span title="Number" style="color:#2F80ED">pv</span>=0, <span title="Boolean" style="color:#27AE60">type</span>=FALSE) => <span title="Number" style="color:#2F80ED">fv</span>**
+```
+
+**Guidelines:**
+
+- Use `title` attribute to specify the data type
+- Use `style="color:#HEXCODE"` for syntax highlighting
+- Use square brackets for optional arguments
+- Show the return type after `=>`
+- Make the entire syntax **bold**
+
+#### 4.2 Argument Descriptions
+
+List each argument with:
+
+- Argument name in _italics_
+- Data type link (e.g., `[number](/features/value-types#numbers)`)
+- Required or optional indicator
+- Description
+
+**Format:**
+
+```markdown
+### Argument descriptions
+
+- _argname_ ([datatype](/features/value-types#datatype), [required|optional](/features/optional-arguments.md)). Description of the argument.
+```
+
+**Example:**
+
+```markdown
+### Argument descriptions
+
+- _rate_ ([number](/features/value-types#numbers), required). The fixed percentage interest rate or yield per period.
+- _pv_ ([number](/features/value-types#numbers), [optional](/features/optional-arguments.md)). "pv" is the <u>p</u>resent <u>v</u>alue or starting amount of the asset (default 0).
+- _type_ ([Boolean](/features/value-types#booleans), [optional](/features/optional-arguments.md)). A logical value indicating whether the payment due dates are at the end (FALSE or 0) of the compounding periods or at the beginning (TRUE or any non-zero value). The default is FALSE when omitted.
+```
+
+**Guidelines:**
+
+- Use bullet points (`*`)
+- Italicize argument names with `*argname*`
+- Link to value types documentation
+- Link to optional arguments page when applicable
+- Expand acronyms in descriptions using `<u>` tags if helpful
+- Mention default values for optional arguments
+
+#### 4.3 Additional Guidance
+
+Provide tips, best practices and important notes about using the function:
+
+```markdown
+### Additional guidance
+
+- Make sure that the _rate_ argument specifies the interest rate or yield applicable to the compounding period.
+- The _pmt_ and _pv_ arguments should be expressed in the same currency unit.
+- To ensure a worthwhile result, one of the _pmt_ and _pv_ arguments should be non-zero.
+```
+
+#### 4.4 Returned Value
+
+Describe what the function returns:
+
+```markdown
+### Returned value
+
+FV returns a [number](/features/value-types#numbers) representing the future value expressed in the same [currency unit](/features/units) that was used for the _pmt_ and _pv_ arguments.
+```
+
+Include:
+
+- Return type (with link to value types if applicable)
+- Units or format if relevant
+- Any important characteristics
+
+#### 4.5 Error Conditions
+
+List all error scenarios the function may encounter:
+
+```markdown
+### Error conditions
+
+- In common with many other IronCalc functions, FV propagates errors that are found in any of its arguments.
+- If too few or too many arguments are supplied, FV returns the [`#ERROR!`](/features/error-types.md#error) error.
+- If the value of any of the _rate_, _nper_, _pmt_ or _pv_ arguments is not (or cannot be converted to) a [number](/features/value-types#numbers), then FV returns the [`#VALUE!`](/features/error-types.md#value) error.
+- If the value of the _type_ argument is not (or cannot be converted to) a [Boolean](/features/value-types#booleans), then FV again returns the [`#VALUE!`](/features/error-types.md#value) error.
+- For some combinations of valid argument values, FV may return a [`#NUM!`](/features/error-types.md#num) error or a [`#DIV/0!`](/features/error-types.md#div-0) error.
+```
+
+**Guidelines:**
+
+- Use bullet points
+- Format error types using backticks and link to the error types page: `` [`#ERROR!`](/features/error-types.md#error) ``
+- Reference argument names in italics when discussing specific arguments
+- Add the include directive at the end if using the error details snippet:
+
+```markdown
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+```
+
+### 5. Details (Optional but Recommended)
+
+For functions with mathematical formulas or complex behavior, include a Details section. This section can also include plots, graphs or charts to help clarify the function's behavior. 
+
+```markdown
+## Details
+
+- If $\text{type} \neq 0$, $\text{fv}$ is given by the equation:
+  $$ \text{fv} = -\text{pv} \times (1 + \text{rate})^\text{nper} - \dfrac{\text{pmt}\times\big({(1+\text{rate})^\text{nper}-1}\big) \times(1+\text{rate})}{\text{rate}}$$
+
+- If $\text{type} = 0$, $\text{fv}$ is given by the equation:
+  $$ \text{fv} = -\text{pv} \times (1 + \text{rate})^{\text{nper}} - \dfrac{\text{pmt}\times\big({(1+\text{rate})^\text{nper}-1}\big)}{\text{rate}}$$
+```
+
+**Guidelines:**
+
+- Use LaTeX math notation with `$` for inline and `$$` for block equations
+- Use `\text{}` for variable names in equations
+- Explain special cases or edge conditions
+
+### 6. Examples
+
+Link to interactive examples in IronCalc:
+
+```markdown
+## Examples
+
+[See some examples in IronCalc](https://app.ironcalc.com/?example=functionname).
+```
+
+Replace `functionname` with the actual function name (lowercase).
+
+### 7. Links
+
+Provide external references and related functions:
+
+```markdown
+## Links
+
+- For more information about the concept of "future value" in finance, visit Wikipedia's [Future value](https://en.wikipedia.org/wiki/Future_value) page.
+- See also IronCalc's [NPER](/functions/financial/nper), [PMT](/functions/financial/pmt), [PV](/functions/financial/pv) and [RATE](/functions/financial/rate) functions.
+- Visit Microsoft Excel's [FV function](https://support.microsoft.com/en-gb/office/fv-function-2eef9f44-a084-4c61-bdd8-4fe4bb1b71b3) page.
+- Both [Google Sheets](https://support.google.com/docs/answer/3093224) and [LibreOffice Calc](https://wiki.documentfoundation.org/Documentation/Calc_Functions/FV) provide versions of the FV function.
+```
+
+**Guidelines:**
+
+- Include Wikipedia links for concepts when available
+- Link to related IronCalc functions in the same category
+- Include links to equivalent functions in Excel, Google Sheets, and LibreOffice Calc
+- Use bullet points
+
+## Syntax Coloring Reference
+
+### Color Codes
+
+| Data Type   | Hex Color | Usage                                   |
+| ----------- | --------- | --------------------------------------- |
+| Number      | `#2F80ED` | All numeric arguments and return values |
+| Boolean     | `#27AE60` | TRUE/FALSE arguments                    |
+| Text/String | `#F2994A` | Text arguments                          |
+| Array/Range | `#EB5757` | Array or range arguments                |
+
+### Syntax Highlighting Template
+
+```html
+<span title="Type" style="color:#HEXCODE">argument_name</span>
+```
+
+**Examples:**
+
+- Number: `<span title="Number" style="color:#2F80ED">rate</span>`
+- Boolean: `<span title="Boolean" style="color:#27AE60">type</span>`
+- Text: `<span title="Text" style="color:#F2994A">text</span>`
+
+## Formatting Conventions
+
+### Text Formatting
+
+- **Function names**: Use exact case as in IronCalc
+- **Argument names**: Use _italics_ when referencing in prose
+- **Acronyms**: Expand using `<u>` tags: `<u>F</u>uture <u>V</u>alue`
+- **Code/values**: Use backticks for error codes: `` `#ERROR!` ``
+- **Links**: Use descriptive link text, not raw URLs
+
+### Section Headers
+
+- Use `#` for the page title with the function name (e.g., FV Function)
+- Use `##` for main sections (Overview, Usage, Details, Examples, Links)
+- Use `###` for subsections (Syntax, Argument descriptions, etc.)
+
+### Lists
+
+- Use bullet points (`*`) for argument descriptions and error conditions
+- Use numbered lists only when order matters
+
+## Checklist
+
+Before submitting a function documentation, ensure:
+
+- [ ] Frontmatter is correct
+- [ ] Title follows the format "FUNCTION_NAME function"
+- [ ] Overview clearly explains the function's purpose
+- [ ] Syntax is color-coded correctly
+- [ ] All arguments are documented with correct types
+- [ ] Required vs optional arguments are clearly marked
+- [ ] Return value is described
+- [ ] Error conditions are comprehensive
+- [ ] Examples link is included
+- [ ] Links section includes relevant references
+- [ ] Mathematical formulas (if any) use proper LaTeX syntax
+- [ ] All internal links use relative paths
+- [ ] Spelling and grammar are correct
+
+## Example Template
+
+```markdown
+---
+layout: doc
+outline: deep
+lang: en-US
+---
+
+# FUNCTION_NAME function
+
+::: warning
+**Note:** This draft page is under construction 🚧
+:::
+
+## Overview
+
+FUNCTION_NAME (<u>A</u>cronym <u>E</u>xplanation) is a function of the [Category] category that can be used to [primary purpose].
+
+[Additional context about when to use this function or related functions.]
+
+## Usage
+
+### Syntax
+
+**FUNCTION_NAME(<span title="Type" style="color:#2F80ED">arg1</span>, [<span title="Type" style="color:#2F80ED">arg2</span>], [<span title="Boolean" style="color:#27AE60">arg3</span>]) => <span title="Type" style="color:#2F80ED">return_value</span>**
+
+### Argument descriptions
+
+- _arg1_ ([type](/features/value-types#type), required). Description.
+- _arg2_ ([type](/features/value-types#type), [optional](/features/optional-arguments.md)). Description (default value).
+- _arg3_ ([Boolean](/features/value-types#booleans), [optional](/features/optional-arguments.md)). Description (default FALSE).
+
+### Additional guidance
+
+- Tip or best practice.
+- Another important note.
+
+### Returned value
+
+FUNCTION_NAME returns a [type](/features/value-types#type) representing [description].
+
+### Error conditions
+
+- General error propagation note.
+- Specific error condition with [`#ERROR!`](/features/error-types.md#error) link.
+- Another error condition.
+
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+
+## Details
+
+[Mathematical formulas or detailed explanations if needed]
+
+## Examples
+
+[See some examples in IronCalc](https://app.ironcalc.com/?example=functionname).
+
+## Links
+
+- Wikipedia link if applicable.
+- Related IronCalc functions.
+- Microsoft Excel documentation.
+- Google Sheets and LibreOffice Calc links.
+```
+
+## Questions?
+
+If you have questions about documenting functions, reach out on our [Discord Channel](https://discord.com/invite/zZYWfh3RHJ) or check existing function documentation for examples.

docs/src/contributing/how-to-contribute.md

@@ -6,4 +6,10 @@ lang: en-US
 
 # How to Contribute
 
-If you want to give us a hand, take a look at our [GitHub repository](https://github.com/ironcalc/IronCalc?tab=readme-ov-file#collaborators-needed-call-to-action), join our [Discord Channel](https://discord.com/invite/zZYWfh3RHJ) or send us an email to [hello@ironcalc.com](mailto:hello@ironcalc.com).
+If you want to give us a hand, take a look at our [GitHub repository](https://github.com/ironcalc/IronCalc?tab=readme-ov-file#collaborators-needed-call-to-action) – we've marked some issues there with the tag 'good first issue' that could serve you as a starting point.
+
+If you also want to discuss topics, share your thoughts or just say 'hi', you can join our [Discord Channel](https://discord.com/invite/zZYWfh3RHJ) or send us an email to [hello@ironcalc.com](mailto:hello@ironcalc.com).
+
+## Documentation
+
+If you're interested in contributing to our documentation, especially function documentation, please see our [Function Documentation Guide](/contributing/function-documentation-guide).

docs/src/features/value-types.md

@@ -68,6 +68,8 @@ Using IronCalc, a complex number is a string of the form "1+j3".
 
 ## Arrays
 
+## Ranges
+
 ## References
 
 A reference is a pointer to a single cell or a range of cells. The reference can either be entered manually, for example "A4", or as the result of a calculation, such as the OFFSET Function or the INDIRECT Function. A reference can also be built, for example with the Colon (\:) Operator. 

docs/src/functions/date-and-time.md

@@ -6,33 +6,32 @@ lang: en-US
 
 # Date and Time functions
 
-At the moment IronCalc only supports a few function in this section.  
-You can track the progress in this [GitHub issue](https://github.com/ironcalc/IronCalc/issues/48).
+All Date and Time functions are already supported in IronCalc.
 
 | Function         | Status                                         | Documentation |
 | ---------------- | ---------------------------------------------- | ------------- |
 | DATE             | <Badge type="tip" text="Available" />          | –             |
-| DATEDIF          | <Badge type="info" text="Not implemented yet" /> | –             |
-| DATEVALUE        | <Badge type="info" text="Not implemented yet" /> | –             |
+| DATEDIF          | <Badge type="tip" text="Available" />          | –             |
+| DATEVALUE        | <Badge type="tip" text="Available" />          | [DATEVALUE](date_and_time/datevalue) |
 | DAY              | <Badge type="tip" text="Available" />          | [DAY](date_and_time/day) |
-| DAYS             | <Badge type="info" text="Not implemented yet" /> | –             |
-| DAYS360          | <Badge type="info" text="Not implemented yet" /> | –             |
+| DAYS             | <Badge type="tip" text="Available" />          | –             |
+| DAYS360          | <Badge type="tip" text="Available" />          | –             |
 | EDATE            | <Badge type="tip" text="Available" />          | –             |
 | EOMONTH          | <Badge type="tip" text="Available" />          | –             |
-| HOUR             | <Badge type="info" text="Not implemented yet" /> | –             |
-| ISOWEEKNUM       | <Badge type="info" text="Not implemented yet" /> | –             |
-| MINUTE           | <Badge type="info" text="Not implemented yet" /> | –             |
+| HOUR             | <Badge type="tip" text="Available" />          | –             |
+| ISOWEEKNUM       | <Badge type="tip" text="Available" />          | –             |
+| MINUTE           | <Badge type="tip" text="Available" />          | –             |
 | MONTH            | <Badge type="tip" text="Available" />          | [MONTH](date_and_time/month) |
-| NETWORKDAYS      | <Badge type="info" text="Not implemented yet" /> | –             |
-| NETWORKDAYS.INTL | <Badge type="info" text="Not implemented yet" /> | –             |
+| NETWORKDAYS      | <Badge type="tip" text="Available" />          | [NETWORKDAYS](date_and_time/networkdays) |
+| NETWORKDAYS.INTL | <Badge type="tip" text="Available" />          | [NETWORKDAYS.INTL](date_and_time/networkdays.intl) |
 | NOW              | <Badge type="tip" text="Available" />          | –             |
-| SECOND           | <Badge type="info" text="Not implemented yet" /> | –             |
-| TIME             | <Badge type="info" text="Not implemented yet" /> | –             |
-| TIMEVALUE        | <Badge type="info" text="Not implemented yet" /> | –             |
+| SECOND           | <Badge type="tip" text="Available" />          | –             |
+| TIME             | <Badge type="tip" text="Available" />          | –             |
+| TIMEVALUE        | <Badge type="tip" text="Available" />          | [TIMEVALUE](date_and_time/timevalue) |
 | TODAY            | <Badge type="tip" text="Available" />          | –             |
-| WEEKDAY          | <Badge type="info" text="Not implemented yet" /> | –             |
-| WEEKNUM          | <Badge type="info" text="Not implemented yet" /> | –             |
-| WORKDAY          | <Badge type="info" text="Not implemented yet" /> | –             |
-| WORKDAY.INTL     | <Badge type="info" text="Not implemented yet" /> | –             |
+| WEEKDAY          | <Badge type="tip" text="Available" />          | –             |
+| WEEKNUM          | <Badge type="tip" text="Available" />          | –             |
+| WORKDAY          | <Badge type="tip" text="Available" />          | –             |
+| WORKDAY.INTL     | <Badge type="tip" text="Available" />          | –             |
 | YEAR             | <Badge type="tip" text="Available" />          | [YEAR](date_and_time/year) |
-| YEARFRAC         | <Badge type="info" text="Not implemented yet" /> | –             |
+| YEARFRAC         | <Badge type="tip" text="Available" />          | –             |

docs/src/functions/date_and_time/datedif.md

@@ -7,6 +7,5 @@ lang: en-US
 # DATEDIF
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/datevalue.md

@@ -4,9 +4,41 @@ outline: deep
 lang: en-US
 ---
 
-# DATEVALUE
+# DATEVALUE function
 
-::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
-:::
+## Overview
+DATEVALUE is a function of the Date and Time category that converts a date stored as text to a [serial number](/features/serial-numbers.md) corresponding to a date value.
+
+## Usage
+### Syntax
+**DATEVALUE(<span title="Text" style="color:#1E88E5">date_text</span>) => <span title="Number" style="color:#1E88E5">datevalue</span>**
+
+### Argument descriptions
+* *date_text* ([text](/features/value-types#strings), required). A text string that represents a date in a known format. The text must represent a date between December 31, 1899 and December 31, 9999.
+
+### Additional guidance
+* If the year portion of the *date_text* argument is omitted, DATEVALUE uses the current year from the system clock.
+* Time information in the *date_text* argument is ignored. DATEVALUE processes only the date portion.
+
+### Returned value
+DATEVALUE returns a [number](/features/value-types#numbers) that represents the date as a [serial number](/features/serial-numbers.md). The serial number corresponds to the number of days since December 31, 1899.
+
+### Error conditions
+* In common with many other IronCalc functions, DATEVALUE propagates errors that are found in its argument.
+* If no argument, or more than one argument, is supplied, then DATEVALUE returns the [`#ERROR!`](/features/error-types.md#error) error.
+* If the value of the *date_text* argument is not (or cannot be converted to) a [text](/features/value-types#strings) value, then DATEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *date_text* argument represents a date outside the valid range (before December 31, 1899 or after December 31, 9999), then DATEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *date_text* argument cannot be recognized as a valid date format, then DATEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+
+<!-- ## Details
+For more information on how IronCalc processes Date and Time functions and values, visit [Date and Time](/features/serial-numbers.md) 
+
+## Examples
+[See some examples in IronCalc](https://app.ironcalc.com/?example=datevalue).
+-->
+
+## Links
+* See also IronCalc's [TIMEVALUE](/functions/date_and_time/timevalue.md) function for converting time text to serial numbers.
+* Visit Microsoft Excel's [DATEVALUE function](https://support.microsoft.com/en-us/office/datevalue-function-df8b07d4-7761-4a93-bc33-b7471bbff252) page.
+* Both [Google Sheets](https://support.google.com/docs/answer/3093039) and [LibreOffice Calc](https://wiki.documentfoundation.org/Documentation/Calc_Functions/DATEVALUE) provide versions of the DATEVALUE function.

docs/src/functions/date_and_time/days.md

@@ -7,6 +7,5 @@ lang: en-US
 # DAYS
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/days360.md

@@ -7,6 +7,5 @@ lang: en-US
 # DAYS360
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/hour.md

@@ -7,6 +7,6 @@ lang: en-US
 # HOUR
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+**Note:** This draft page is under construction 🚧
+The HOUR function is implemented and available in IronCalc.
 :::

docs/src/functions/date_and_time/isoweeknum.md

@@ -7,6 +7,5 @@ lang: en-US
 # ISOWEEKNUM
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/minute.md

@@ -7,6 +7,6 @@ lang: en-US
 # MINUTE
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+**Note:** This draft page is under construction 🚧
+The MINUTE function is implemented and available in IronCalc.
 :::

docs/src/functions/date_and_time/networkdays.intl.md

@@ -4,9 +4,73 @@ outline: deep
 lang: en-US
 ---
 
-# NETWORKDAYS.INTL
+# NETWORKDAYS.INTL function
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
-:::
+**Note:** This draft page is under construction 🚧
+:::
+
+## Overview
+NETWORKDAYS.INTL is a function of the Date and Time category that calculates the number of working days between two dates, with customizable weekend definitions and optionally specified holidays.
+
+## Usage
+
+### Syntax
+**NETWORKDAYS.INTL(<span title="Number" style="color:#1E88E5">start_date</span>, <span title="Number" style="color:#1E88E5">end_date</span>, [<span title="Number or String" style="color:#4CAF50">weekend</span>], [<span title="Array" style="color:#E91E63">holidays</span>]) => <span title="Number" style="color:#1E88E5">workdays</span>**
+
+### Argument descriptions
+* *start_date* ([number](/features/value-types#numbers), required). The start date expressed as a [serial number](/features/serial-numbers.md).
+* *end_date* ([number](/features/value-types#numbers), required). The end date expressed as a [serial number](/features/serial-numbers.md).
+* *weekend* ([number](/features/value-types#numbers) or [string](/features/value-types#strings), optional). Defines which days are considered weekends. Default is 1 (Saturday-Sunday).
+* *holidays* ([array](/features/value-types#arrays) or [range](/features/value-types#ranges), optional). A list of dates to exclude from the calculation, expressed as serial numbers.
+
+### Weekend parameter options
+The _weekend_ parameter can be specified in two ways:
+
+**Numeric codes:**
+- 1 (default): Saturday and Sunday
+- 2: Sunday and Monday
+- 3: Monday and Tuesday
+- 4: Tuesday and Wednesday
+- 5: Wednesday and Thursday
+- 6: Thursday and Friday
+- 7: Friday and Saturday
+- 11: Sunday only
+- 12: Monday only
+- 13: Tuesday only
+- 14: Wednesday only
+- 15: Thursday only
+- 16: Friday only
+- 17: Saturday only
+
+**String pattern:** A 7-character string of "0" and "1" where "1" indicates a weekend day. The string represents Monday through Sunday. For example, "0000011" means Saturday and Sunday are weekends.
+
+### Additional guidance
+- If the supplied _start_date_ and _end_date_ arguments have fractional parts, NETWORKDAYS.INTL uses their [floor values](https://en.wikipedia.org/wiki/Floor_and_ceiling_functions).
+- If _start_date_ is later than _end_date_, the function returns a negative number.
+- Empty cells in the _holidays_ array are ignored.
+- The calculation includes both the start and end dates if they are workdays.
+
+### Returned value
+NETWORKDAYS.INTL returns a [number](/features/value-types#numbers) representing the count of working days between the two dates.
+
+### Error conditions
+* In common with many other IronCalc functions, NETWORKDAYS.INTL propagates errors that are found in its arguments.
+* If fewer than 2 or more than 4 arguments are supplied, then NETWORKDAYS.INTL returns the [`#ERROR!`](/features/error-types.md#error) error.
+* If the *start_date* or *end_date* arguments are not (or cannot be converted to) [numbers](/features/value-types#numbers), then NETWORKDAYS.INTL returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *start_date* or *end_date* values are outside the valid date range, then NETWORKDAYS.INTL returns the [`#NUM!`](/features/error-types.md#num) error.
+* If the *weekend* parameter is an invalid numeric code or an improperly formatted string, then NETWORKDAYS.INTL returns the [`#NUM!`](/features/error-types.md#num) or [`#VALUE!`](/features/error-types.md#value) error.
+* If the *holidays* array contains non-numeric values, then NETWORKDAYS.INTL returns the [`#VALUE!`](/features/error-types.md#value) error.
+
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+
+## Details
+IronCalc utilizes Rust's [chrono](https://docs.rs/chrono/latest/chrono/) crate to implement the NETWORKDAYS.INTL function. This function provides more flexibility than NETWORKDAYS by allowing custom weekend definitions.
+
+## Examples
+[See some examples in IronCalc](https://app.ironcalc.com/?example=networkdays-intl).
+
+## Links
+* See also IronCalc's [NETWORKDAYS](/functions/date_and_time/networkdays.md) function for the basic version with fixed weekends.
+* Visit Microsoft Excel's [NETWORKDAYS.INTL function](https://support.microsoft.com/en-us/office/networkdays-intl-function-a9b26239-4f20-46a1-9ab8-4e925bfd5e28) page.
+* Both [Google Sheets](https://support.google.com/docs/answer/3093019) and [LibreOffice Calc](https://wiki.documentfoundation.org/Documentation/Calc_Functions/NETWORKDAYS.INTL) provide versions of the NETWORKDAYS.INTL function.

docs/src/functions/date_and_time/networkdays.md

@@ -4,9 +4,51 @@ outline: deep
 lang: en-US
 ---
 
-# NETWORKDAYS
+# NETWORKDAYS function
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
-:::
+**Note:** This draft page is under construction 🚧
+:::
+
+## Overview
+NETWORKDAYS is a function of the Date and Time category that calculates the number of working days between two dates, excluding weekends (Saturday and Sunday by default) and optionally specified holidays.
+
+## Usage
+
+### Syntax
+**NETWORKDAYS(<span title="Number" style="color:#1E88E5">start_date</span>, <span title="Number" style="color:#1E88E5">end_date</span>, [<span title="Array" style="color:#E91E63">holidays</span>]) => <span title="Number" style="color:#1E88E5">workdays</span>**
+
+### Argument descriptions
+* *start_date* ([number](/features/value-types#numbers), required). The start date expressed as a [serial number](/features/serial-numbers.md).
+* *end_date* ([number](/features/value-types#numbers), required). The end date expressed as a [serial number](/features/serial-numbers.md).
+* *holidays* ([array](/features/value-types#arrays) or [range](/features/value-types#ranges), optional). A list of dates to exclude from the calculation, expressed as serial numbers.
+
+### Additional guidance
+- If the supplied _start_date_ and _end_date_ arguments have fractional parts, NETWORKDAYS uses their [floor values](https://en.wikipedia.org/wiki/Floor_and_ceiling_functions).
+- If _start_date_ is later than _end_date_, the function returns a negative number.
+- Weekend days are Saturday and Sunday by default. Use [NETWORKDAYS.INTL](networkdays.intl) for custom weekend definitions.
+- Empty cells in the _holidays_ array are ignored.
+- The calculation includes both the start and end dates if they are workdays.
+
+### Returned value
+NETWORKDAYS returns a [number](/features/value-types#numbers) representing the count of working days between the two dates.
+
+### Error conditions
+* In common with many other IronCalc functions, NETWORKDAYS propagates errors that are found in its arguments.
+* If fewer than 2 or more than 3 arguments are supplied, then NETWORKDAYS returns the [`#ERROR!`](/features/error-types.md#error) error.
+* If the *start_date* or *end_date* arguments are not (or cannot be converted to) [numbers](/features/value-types#numbers), then NETWORKDAYS returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *start_date* or *end_date* values are outside the valid date range, then NETWORKDAYS returns the [`#NUM!`](/features/error-types.md#num) error.
+* If the *holidays* array contains non-numeric values, then NETWORKDAYS returns the [`#VALUE!`](/features/error-types.md#value) error.
+
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+
+## Details
+IronCalc utilizes Rust's [chrono](https://docs.rs/chrono/latest/chrono/) crate to implement the NETWORKDAYS function. The function treats Saturday and Sunday as weekend days.
+
+## Examples
+[See some examples in IronCalc](https://app.ironcalc.com/?example=networkdays).
+
+## Links
+* See also IronCalc's [NETWORKDAYS.INTL](/functions/date_and_time/networkdays.intl.md) function for custom weekend definitions.
+* Visit Microsoft Excel's [NETWORKDAYS function](https://support.microsoft.com/en-us/office/networkdays-function-48e717bf-a7a3-495f-969e-5005e3eb18e7) page.
+* Both [Google Sheets](https://support.google.com/docs/answer/3093018) and [LibreOffice Calc](https://wiki.documentfoundation.org/Documentation/Calc_Functions/NETWORKDAYS) provide versions of the NETWORKDAYS function.

docs/src/functions/date_and_time/second.md

@@ -7,6 +7,6 @@ lang: en-US
 # SECOND
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+**Note:** This draft page is under construction 🚧
+The SECOND function is implemented and available in IronCalc.
 :::

docs/src/functions/date_and_time/time.md

@@ -7,6 +7,6 @@ lang: en-US
 # TIME
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+**Note:** This draft page is under construction 🚧
+The TIME function is implemented and available in IronCalc.
 :::

docs/src/functions/date_and_time/timevalue.md

@@ -4,9 +4,42 @@ outline: deep
 lang: en-US
 ---
 
-# TIMEVALUE
+# TIMEVALUE function
 
-::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
-:::
+## Overview
+TIMEVALUE is a function of the Date and Time category that converts a time stored as text to a [serial number](/features/serial-numbers.md) corresponding to a time value. The serial number represents time as a decimal fraction of a 24-hour day (e.g., 0.5 represents 12:00:00 noon).
+
+## Usage
+### Syntax
+**TIMEVALUE(<span title="Text" style="color:#1E88E5">time_text</span>) => <span title="Number" style="color:#1E88E5">timevalue</span>**
+
+### Argument descriptions
+* *time_text* ([text](/features/value-types#strings), required). A text string that represents a time in a known format. The text must represent a time between 00:00:00 and 23:59:59.
+
+### Additional guidance
+* Date information in the *time_text* argument is ignored. TIMEVALUE processes only the time portion.
+* The function can handle various time formats, including both 12-hour and 24-hour formats, as well as text that includes both date and time information.
+
+### Returned value
+TIMEVALUE returns a [number](/features/value-types#numbers) that represents the time as a [serial number](/features/serial-numbers.md). The serial number is a decimal fraction of a 24-hour day, where:
+* 0.0 represents 00:00:00 (midnight)
+* 0.5 represents 12:00:00 (midday)
+* 0.99999... represents 23:59:59 (just before midnight)
+
+### Error conditions
+* In common with many other IronCalc functions, TIMEVALUE propagates errors that are found in its argument.
+* If no argument, or more than one argument, is supplied, then TIMEVALUE returns the [`#ERROR!`](/features/error-types.md#error) error.
+* If the value of the *time_text* argument is not (or cannot be converted to) a [text](/features/value-types#strings) value, then TIMEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *time_text* argument represents a time outside the valid range, then TIMEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+* If the *time_text* argument cannot be recognized as a valid time format, then TIMEVALUE returns the [`#VALUE!`](/features/error-types.md#value) error.
+<!--@include: ../markdown-snippets/error-type-details.txt-->
+
+<!--
+## Examples
+[See some examples in IronCalc](https://app.ironcalc.com/?example=timevalue).
+-->
+
+## Links
+* See also IronCalc's [DATEVALUE](/functions/date_and_time/datevalue.md) function for converting date text to serial numbers.
+* Visit Microsoft Excel's [TIMEVALUE function](https://support.microsoft.com/en-us/office/timevalue-function-0b615c12-33d8-4431-bf3d-f3eb6d186645) page.
+* Both [Google Sheets](https://support.google.com/docs/answer/3267350) and [LibreOffice Calc](https://wiki.documentfoundation.org/Documentation/Calc_Functions/TIMEVALUE) provide versions of the TIMEVALUE function.

docs/src/functions/date_and_time/weekday.md

@@ -7,6 +7,5 @@ lang: en-US
 # WEEKDAY
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/weeknum.md

@@ -7,6 +7,5 @@ lang: en-US
 # WEEKNUM
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/workday.intl.md

@@ -7,6 +7,5 @@ lang: en-US
 # WORKDAY.INTL
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/workday.md

@@ -7,6 +7,5 @@ lang: en-US
 # WORKDAY
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/date_and_time/yearfrac.md

@@ -7,6 +7,5 @@ lang: en-US
 # YEARFRAC
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::

docs/src/functions/math-and-trigonometry.md

@@ -14,10 +14,10 @@ You can track the progress in this [GitHub issue](https://github.com/ironcalc/Ir
 | ABS             | <Badge type="tip" text="Available" />          | –             |
 | ACOS            | <Badge type="tip" text="Available" />          | [ACOS](math_and_trigonometry/acos) |
 | ACOSH           | <Badge type="tip" text="Available" />          | [ACOSH](math_and_trigonometry/acosh) |
-| ACOT            | <Badge type="info" text="Not implemented yet" /> | –             |
-| ACOTH           | <Badge type="info" text="Not implemented yet" /> | –             |
+| ACOT            | <Badge type="tip" text="Available" />          | –             |
+| ACOTH           | <Badge type="tip" text="Available" />          | –             |
 | AGGREGATE       | <Badge type="info" text="Not implemented yet" /> | –             |
-| ARABIC          | <Badge type="info" text="Not implemented yet" /> | –             |
+| ARABIC          | <Badge type="tip" text="Available" />          | –             |
 | ASIN            | <Badge type="tip" text="Available" />          | [ASIN](math_and_trigonometry/asin) |
 | ASINH           | <Badge type="tip" text="Available" />          | [ASINH](math_and_trigonometry/asinh) |
 | ATAN            | <Badge type="tip" text="Available" />          | [ATAN](math_and_trigonometry/atan) |
@@ -27,64 +27,64 @@ You can track the progress in this [GitHub issue](https://github.com/ironcalc/Ir
 | CEILING         | <Badge type="info" text="Not implemented yet" /> | –             |
 | CEILING.MATH    | <Badge type="info" text="Not implemented yet" /> | –             |
 | CEILING.PRECISE | <Badge type="info" text="Not implemented yet" /> | –             |
-| COMBIN          | <Badge type="info" text="Not implemented yet" /> | –             |
-| COMBINA         | <Badge type="info" text="Not implemented yet" /> | –             |
+| COMBIN          | <Badge type="tip" text="Available" />          | –             |
+| COMBINA         | <Badge type="tip" text="Available" />          | –             |
 | COS             | <Badge type="tip" text="Available" />          | [COS](math_and_trigonometry/cos) |
 | COSH            | <Badge type="tip" text="Available" />          | [COSH](math_and_trigonometry/cosh) |
-| COT             | <Badge type="info" text="Not implemented yet" /> | –             |
-| COTH            | <Badge type="info" text="Not implemented yet" /> | –             |
-| CSC             | <Badge type="info" text="Not implemented yet" /> | –             |
-| CSCH            | <Badge type="info" text="Not implemented yet" /> | –             |
+| COT             | <Badge type="tip" text="Available" />          | –             |
+| COTH            | <Badge type="tip" text="Available" />          | –             |
+| CSC             | <Badge type="tip" text="Available" />          | –             |
+| CSCH            | <Badge type="tip" text="Available" />          | –             |
 | DECIMAL         | <Badge type="info" text="Not implemented yet" /> | –             |
-| DEGREES         | <Badge type="info" text="Not implemented yet" /> | –             |
-| EVEN            | <Badge type="info" text="Not implemented yet" /> | –             |
-| EXP             | <Badge type="info" text="Not implemented yet" /> | –             |
+| DEGREES         | <Badge type="tip" text="Available" /> | [DEGREES](math_and_trigonometry/degrees) |
+| EVEN            | <Badge type="tip" text="Available" /> | [EVEN](math_and_trigonometry/even) |
+| EXP             | <Badge type="tip" text="Available" /> | –             |
 | FACT            | <Badge type="info" text="Not implemented yet" /> | –             |
 | FACTDOUBLE      | <Badge type="info" text="Not implemented yet" /> | –             |
 | FLOOR           | <Badge type="info" text="Not implemented yet" /> | –             |
 | FLOOR.MATH      | <Badge type="info" text="Not implemented yet" /> | –             |
 | FLOOR.PRECISE   | <Badge type="info" text="Not implemented yet" /> | –             |
 | GCD             | <Badge type="info" text="Not implemented yet" /> | –             |
-| INT             | <Badge type="info" text="Not implemented yet" /> | –             |
+| INT             | <Badge type="tip" text="Available" />          | –             |
 | ISO.CEILING     | <Badge type="info" text="Not implemented yet" /> | –             |
 | LCM             | <Badge type="info" text="Not implemented yet" /> | –             |
 | LET             | <Badge type="info" text="Not implemented yet" /> | –             |
-| LN              | <Badge type="info" text="Available" />           | –             |
-| LOG             | <Badge type="info" text="Available" />           | –             |
-| LOG10           | <Badge type="info" text="Available" />           | –             |
+| LN              | <Badge type="tip" text="Available" />           | –             |
+| LOG             | <Badge type="tip" text="Available" />           | –             |
+| LOG10           | <Badge type="tip" text="Available" />           | –             |
 | MDETERM         | <Badge type="info" text="Not implemented yet" /> | –             |
 | MINVERSE        | <Badge type="info" text="Not implemented yet" /> | –             |
 | MMULT           | <Badge type="info" text="Not implemented yet" /> | –             |
-| MOD             | <Badge type="info" text="Not implemented yet" /> | –             |
-| MROUND          | <Badge type="info" text="Not implemented yet" /> | –             |
+| MOD             | <Badge type="tip" text="Available" />          | [MOD](math_and_trigonometry/mod) |
+| MROUND          | <Badge type="tip" text="Available" />          | –             |
 | MULTINOMIAL     | <Badge type="info" text="Not implemented yet" /> | –             |
 | MUNIT           | <Badge type="info" text="Not implemented yet" /> | –             |
-| ODD             | <Badge type="info" text="Not implemented yet" /> | –             |
+| ODD             | <Badge type="tip" text="Available" /> | [ODD](math_and_trigonometry/odd) |
 | PI              | <Badge type="info" text="Not implemented yet" /> | –             |
 | POWER           | <Badge type="tip" text="Available" />          | –             |
 | PRODUCT         | <Badge type="tip" text="Available" />          | –             |
-| QUOTIENT        | <Badge type="info" text="Not implemented yet" /> | –             |
-| RADIANS         | <Badge type="info" text="Not implemented yet" /> | –             |
+| QUOTIENT        | <Badge type="tip" text="Available" /> | [QUOTIENT](math_and_trigonometry/quotient) |
+| RADIANS         | <Badge type="tip" text="Available" /> | [RADIANS](math_and_trigonometry/radians) |
 | RAND            | <Badge type="tip" text="Available" />          | –             |
 | RANDARRAY       | <Badge type="info" text="Not implemented yet" /> | –             |
 | RANDBETWEEN     | <Badge type="tip" text="Available" />          | –             |
-| ROMAN           | <Badge type="info" text="Not implemented yet" /> | –             |
+| ROMAN           | <Badge type="tip" text="Available" />          | –             |
 | ROUND           | <Badge type="tip" text="Available" />          | –             |
 | ROUNDDOWN       | <Badge type="tip" text="Available" />          | –             |
 | ROUNDUP         | <Badge type="tip" text="Available" />          | –             |
-| SEC             | <Badge type="info" text="Not implemented yet" /> | –             |
-| SECH            | <Badge type="info" text="Not implemented yet" /> | –             |
+| SEC             | <Badge type="tip" text="Available" />          | –             |
+| SECH            | <Badge type="tip" text="Available" />          | –             |
 | SERIESSUM       | <Badge type="info" text="Not implemented yet" /> | –             |
 | SEQUENCE        | <Badge type="info" text="Not implemented yet" /> | –             |
-| SIGN            | <Badge type="info" text="Not implemented yet" /> | –             |
+| SIGN            | <Badge type="tip" text="Available" /> | –             |
 | SIN             | <Badge type="tip" text="Available" />          | [SIN](math_and_trigonometry/sin) |
 | SINH            | <Badge type="tip" text="Available" />          | [SINH](math_and_trigonometry/sinh) |
 | SQRT            | <Badge type="tip" text="Available" />          | –             |
-| SQRTPI          | <Badge type="info" text="Available" />         | –             |
+| SQRTPI          | <Badge type="tip" text="Available" />         | –             |
 | SUBTOTAL        | <Badge type="info" text="Not implemented yet" /> | –             |
 | SUM             | <Badge type="tip" text="Available" />          | –             |
 | SUMIF           | <Badge type="tip" text="Available" />          | –             |
-| SUMIFS          | <Badge type="info" text="Available" />         | –             |
+| SUMIFS          | <Badge type="tip" text="Available" />         | –             |
 | SUMPRODUCT      | <Badge type="info" text="Not implemented yet" /> | –             |
 | SUMSQ           | <Badge type="info" text="Not implemented yet" /> | –             |
 | SUMX2MY2        | <Badge type="info" text="Not implemented yet" /> | –             |
@@ -92,4 +92,4 @@ You can track the progress in this [GitHub issue](https://github.com/ironcalc/Ir
 | SUMXMY2         | <Badge type="info" text="Not implemented yet" /> | –             |
 | TAN             | <Badge type="tip" text="Available" />          | [TAN](math_and_trigonometry/tan) |
 | TANH            | <Badge type="tip" text="Available" />          | [TANH](math_and_trigonometry/tanh) |
-| TRUNC           | <Badge type="info" text="Not implemented yet" /> | –             |
+| TRUNC           | <Badge type="tip" text="Available" />          | –             |

docs/src/functions/math_and_trigonometry/acot.md

@@ -7,6 +7,5 @@ lang: en-US
 # ACOT
 
 ::: warning
-🚧 This function is not yet available in IronCalc.
-[Follow development here](https://github.com/ironcalc/IronCalc/labels/Functions)
+🚧 This function is implemented but currently lacks detailed documentation. For guidance, you may refer to the equivalent functionality in [Microsoft Excel documentation](https://support.microsoft.com/en-us/office/excel-functions-by-category-5f91f4e9-7b42-46d2-9bd1-63f26a86c0eb).
 :::