Excel incorrectly assumes that the year 1900 is a leap year - Microsoft 365 Apps
learn.microsoft.com
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.
  • over_clox@lemmy.worldEnglish
    28·
    6 months ago

    TL;DR - M$ Excel copied the bug from Lotus 123 for backwards fucked up compatibility.

    Saved you the read, you’re welcome.

    • Peer@discuss.tchncs.deEnglish
      2·
      6 months ago

      Probably in the time lotus was released people would use it for relatively simple calculations involving dates that would not go that far back. So this bug would not be a problem for those uses and go undetected for some time. Or maybe it even was a deliberate choice to improve performance since the creator would consider it unlikely to use dates decades away.

      • Kairos@lemmy.todayEnglish
        2·
        6 months ago

        Much more likely : they just had a %4 and only added the %100 case when they tested dates with the year 2000. What about 1800? Can someone test this?

  • antlion@lemmy.dbzer0.comEnglish
    1·
    6 months ago

    Also for any numeric less than 1 expressed as a date/time will display as January 0, 1900. Because January 1st is day 1. Kind of a shame because they really have an opportunity to support more dates in the past with negative values.