this is using epoch "year=0, month=0, day=1", which is pretty unusual for day-based timestamps. Turbo Pascal and its descendants use "days since dec 30, 1899":

this is using epoch "year=0, month=0, day=1", which is pretty unusual for day-based timestamps. Turbo Pascal and its descendants use "days since dec 30, 1899": https://docwiki.embarcadero.com/Libraries/Sydney/en/System.TDateTime https://docwiki.embarcadero.com/Libraries/Sydney/en/System.T... Microsoft Excel uses "days elapsed since January 1, 1900", except on Mac where it uses 1904 as a base (because Microsoft!): https://support.microsoft.com/en-us/office/date-systems-in-excel-e7fe7167-48a9-4b96-bb53-5612a800b487 https://support.microsoft.com/en-us/office/date-systems-in-e...