Class SheetDate

A date in a cell formula: the Excel serial number (1900 date system: 1 = 1900-01-01, with Excel's 1900-02-29; the fraction is the time of day). It counts as a number (arithmetic, ISNUMBER) and stays a date through =A2, IF, lookups and date ± number; MIN/MAX and other arithmetic give a number (like Excel's values). The table shows it as Date.

Example

dateToSerial(new Date(2026, 9, 16));   // 46311
Copy

Since

1.1.99