Does anyone else remember the weirdness with dates in Excel files? On Windows, they used 1900 as the epoch, and on the mac they used 1904 (like the Mac itself), so if you got a spreadsheet from someone on a windows machine, dates would sometimes shift by 4 years.

https://docs.microsoft.com/en-us/office/troubleshoot/excel/1...

I haven't thought of that in years.