Seeing a number like 46300 where a date should be? Excel stores every date as a serial number: the count of days since 1 January 1900. Convert serial numbers to dates and back here, including times and the older 1904 system.
Why Excel shows dates as numbers
Dates are numbers underneath, which is why you can subtract them or add 30 to get a due date. A date shows as a number when the cell is formatted as General or Number, often after importing data. Fix it with Ctrl + 1 → Date.
In Excel
| To | Do this |
|---|---|
| Show a serial as a date | Format the cell as Date, or =TEXT(A2,"dd-mmm-yyyy") |
| Get the serial of a date | Format the cell as General |
| Convert a date stored as text | =DATEVALUE(A2) |
| Build a date from parts | =DATE(2026,10,5) gives 46300 |
The 1900 leap-year bug
Excel treats 1900 as a leap year, so serial 60 is 29 February 1900, a date that never existed. It was kept for compatibility with Lotus 1-2-3. It only affects dates before March 1900.
Frequently asked questions
What is the 1904 date system?
Older Mac versions of Excel counted days from 1 January 1904. Serial numbers are then 1,462 lower. You’ll find the setting in File → Options → Advanced.
What do decimals mean?
The time of day: 0.25 is 06:00, 0.5 is 12:00 and 0.75 is 18:00.