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Excel Date Converter
Free Excel date converter - serial number to date and back (1900 and 1904 systems) and a fixer for text dates mixed between DD/MM and MM/DD.
Serial number → date
Tue, 9 December 2025 at 00:00
In Excel: select the cell, press Ctrl+1 and choose a Date format.
Date → serial number
46338
The whole number is the day; the decimal is the time (0.5 = midday).
Fix text dates (DD/MM vs MM/DD)
Paste one date per line. Output is unambiguous YYYY-MM-DD that Excel reads correctly in any region.
| Input | YYYY-MM-DD | Serial |
|---|---|---|
| 03/04/2026 | 2026-04-03 | 46115 |
| 13/04/2026 | 2026-04-13 | 46125 |
| 4.5.26 | 2026-05-04 | 46146 |
| 28-02-2026 | 2026-02-28 | 46081 |
Data cleaning, done once
Stop fixing the same data every month.
A Power Query clean-up fixes duplicates, spaces and date formats automatically each time new data arrives. See the data cleaning service.
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- Free tools
- 15
- Time to result
- <2m
- Forms to fill
- 0
- 1Run the tool
- 2Send the output
- 3Get the build
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