FIX: Dates are only valid up to the last day of 9999

base/src/test/test_fn_day.rs

@@ -0,0 +1,15 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_fn_date_arguments() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=DAY(95051806)");
+    model._set("A2", "=DAY(2958465)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#NUM!");
+    assert_eq!(model._get_text("A2"), *"31");
+}