Keep dates clear in a shared spreadsheet

A date such as 03/04 can mean different days to different readers. Agree on the meaning before changing an entire column.

1. Write the expected date order and include the year in the column heading or a short note. Use an unambiguous example to explain the convention.
2. On a copy, check a few values against the original records. Include a date whose day is above twelve, plus one that could be read either way.
3. If dates arrived as text, use the spreadsheet's documented conversion method with the correct locale. Changing the display format alone may leave text unchanged.
4. Apply one clear date display to genuine date values. Sort the complete table and check that the earliest and latest records appear where expected.

Keep the original column until the checks pass. Ask collaborators to use the same convention for new entries.