Spreadsheet utility
Excel Date Serial Converter
Convert between real dates and Excel serial date numbers without sending data to a server.
Builder inputs
Use ISO dates for reliable conversion.
460232026-01-01This converter uses Excel's common 1900 date system, including the historical serial 60 leap-year bug. It does not use the older 1904 date system.How this formula works
- Excel stores dates as serial numbers, where each day increments by one.
- Modern Excel commonly uses the 1900 date system, including its historical leap-year bug.
- This utility does not convert the legacy 1904 date system used by some older Mac workbooks.
- Google Sheets can display serial date numbers too, but date system behavior can vary by import context.
Sample data
| Date | Excel Serial |
|---|---|
| 2026-01-01 | 46023 |
| 2026-05-12 | 46154 |
| 2027-01-01 | 46388 |
Common mistakes
- Dates formatted as text may not convert correctly in spreadsheets.
- Time values add decimal fractions to serial numbers.
- Serial 60 is the 1900 leap-year compatibility edge case; 1904-system workbooks need manual adjustment.
Related formulas
FAQ
Are these formulas generated with AI?
No. The builder uses built-in spreadsheet rules in your browser and does not call an AI service.
Do I need to upload my spreadsheet?
No. Enter ranges and criteria manually. The site does not upload, store, or process spreadsheet files.
Can I copy the generated formula?
Yes. Each output includes a copy button so you can paste the formula into Excel or Google Sheets.