How to convert a date format
Pick the date and the style you need.
1
Choose the date
Use the calendar date from the source document.
2
Pick a preferred style
The main result shows that style; all formats appear below.
3
Check the weekday
A mismatched weekday is a quick signal that day and month were swapped.
What does this tool do?
Different systems expect different date strings: ISO 8601 for data exchange, month-first for US forms and day-first in much of the world. Pick a date and see the same day written each way, plus the weekday to catch ordering mistakes.
The Formula
Same calendar date rendered as ISO 8601, US month-first, European day-first and long textFrequently Asked Questions
Which format is safest for data exchange?
ISO 8601 (YYYY-MM-DD) sorts correctly and cannot be confused with a day-first date. Use it for APIs, filenames and database fields.
Why is 03/04/2026 ambiguous?
It means 4 March in day-first regions and 3 April in month-first regions. The long-text row resolves the ambiguity.