CleanMySheet guide
Standardize mixed date formats in a spreadsheet
CleanMySheet parses common date tokens, Excel serial numbers, and ambiguous slash dates (day>12 treated as DD/MM). Output defaults to YYYY-MM-DD; catalog presets switch to UK or US formats.
Open the cleanerSteps
- Upload the file
- Search “dates” or apply Standardize dates
- Use US to UK date format if you need DD/MM/YYYY
- Hover changed cells to see the conversion reason
Ambiguous 03/04/22
If the first number is greater than 12, it is treated as a day. Otherwise the default is US month-first, matching most CRM exports. Pick the UK preset when your team is day-first.
Related searches this page answers
- standardize dates excel
- fix date format csv
- excel serial date
- convert dates to iso