Day of the Week Calculator
Enter a calendar date and find its weekday in the proleptic Gregorian calendar.
How to find a weekday
Enter a complete calendar date and select “Find weekday.” The result names the weekday, formats the date, and shows its distance from today’s calendar date.
Example: February 29, 2024
The calculation returns Thursday for February 29, 2024. The leap day falls between Wednesday, February 28 and Friday, March 1.
Proleptic Gregorian calendar
The calculator applies today’s Gregorian calendar rules backward across all supported years. This convention is called a proleptic calendar.
Leap years are included
Years divisible by four are usually leap years. Century years qualify only when also divisible by 400. Therefore 2000 and 2024 are leap years, while 1900 is not.
Historical calendar changes
Countries adopted the Gregorian calendar at different times. Historical sources may therefore use a Julian weekday for an early date that differs from this result.
Date range and time zone
Valid dates from years 0001 through 9999 are supported. The calculation treats the input as a UTC calendar date, so time, location, and daylight saving time do not apply.