An Excel date serial is incomplete without the workbook's date system. The 1900 and 1904 systems differ, and the compatibility fiction of 29 February 1900 creates a special edge case.
The paid kit includes an explicit-system Python converter, fractional-day handling, tested boundary values and an import worksheet. It rejects the fictitious day instead of quietly mapping it to a different calendar date.
Scope: nonnegative numeric date serials interpreted with a known 1900 or 1904 system. It does not inspect a workbook or infer its date system from the numbers. CPython 3.12 tests and Microsoft source checks completed 18 October 2026. #Excel #DataMigration
The paid kit includes an explicit-system Python converter, fractional-day handling, tested boundary values and an import worksheet. It rejects the fictitious day instead of quietly mapping it to a different calendar date.
Scope: nonnegative numeric date serials interpreted with a known 1900 or 1904 system. It does not inspect a workbook or infer its date system from the numbers. CPython 3.12 tests and Microsoft source checks completed 18 October 2026. #Excel #DataMigration
Sats-powered reveal
Get the date conversion kit
One payment unlocks this reveal. Save your secret to return. No account needed.
Unlock with Secret
Views: 4
Categories: Articles & Guides [c74], Research & Digital Goods [c75]