Use this free day of week calculator to find what day of the week any date falls on, plus its day of the year and week number.
How to use this calculator
Pick any date, past or future, and press Find Day of Week. You will see the weekday, the day number within the year, and the week number.
Common uses
Check which weekday a birthday, holiday, wedding, or historical date falls on, or plan schedules by week number.
Example
1 January 2025 was a Wednesday.
Frequently asked questions
Which week number system is used?
The ISO week system, where weeks start on Monday.
Can I check dates far in the future?
Yes, any date your browser can select works.