#bug #Excel #history
https://support.microsoft.com/en-us/help/214326/excel-incorrectly-assumes-that-the-year-1900-is-a-leap-year
https://support.microsoft.com/en-us/help/214326/excel-incorrectly-assumes-that-the-year-1900-is-a-leap-year
Docs
Excel incorrectly assumes that the year 1900 is a leap year - Office
Explains why the year 1900 is treated as a leap year in Excel 2000. This article outlines the behaviors that occur if this specific issue is corrected.