You export a CSV from a UK system and double-click it in US Excel — 28/05/2026 suddenly looks like May 28, or something even stranger. The file isn't corrupt. Excel is guessing your date format based on your computer's locale.
This short guide covers why that happens, how to import CSV correctly, and how to batch-fix dates that are already wrong. For the full walkthrough with examples, see the official guide: How to Fix Excel CSV Date Import Problems.
Why Excel breaks CSV dates
A CSV is plain text. It does not store whether a value is a date or a string. When you double-click to open, Excel parses using your regional settings:
US Excel: MM/DD/YYYY
