CleanMySheet guide

Standardize mixed date formats in a spreadsheet

CleanMySheet infers day-first vs month-first from unambiguous samples in the column (14/03 must be DMY; 03/14 must be MDY). Output defaults to YYYY-MM-DD. Catalog presets write DD/MM/YYYY or MM/DD/YYYY. Ambiguous 03/04/2022 is left unchanged if the column does not reveal the order.

Date issues will be highlighted after scan.

Steps

1. Upload the file
2. Search “dates” or apply Standardize dates
3. Use Dates as DD/MM/YYYY if you need that output
4. Hover changed cells to see the conversion reason