For example, January 1st, 1999 is 99001 in Julian format. Many older applications store dates like this, and while Excel doesn't recognize this date format by default, that can be solved with a ...

For example, Excel will automatically choose the date format for a cell that contains 11/11/19. You can set Excel to display dates in a variety of ways, no matter how you type in the data.

These serial numbers constitute Excel's internal storage format for date entries. For example, "2012" entered into a date-formatted cell becomes July 5, 1909 in Excel for the Mac and July 4, 1905 ...

Excel may return a serial number instead of a date; because it is stored thus in the backend. Learn how to convert Serial Number to Date.