Day of the Week Calculator
Find out what day of the week a given date falls on.
How to use the Day of the Week Calculator
- Set Date to the day you want to check; the field starts on 2026-01-01.
- Press Calculate to see which weekday that date falls on.
- The line below repeats the date and names its weekday, Thursday for that default.
- Change the date and press Calculate again; past and future both work.
The leap year rule the answer rests on
A year is a leap year when it divides by 4, except century years, which must also divide by 400. That exception is why 1900 was an ordinary year while 2000 was not, and getting it wrong shifts every later weekday by one.
| Year | Divides by 4 | Century exception | Leap year |
|---|---|---|---|
| 1900 | yes | not by 400 | no |
| 2000 | yes | also by 400 | yes |
| 2024 | yes | not a century | yes |
| 2025 | no | not a century | no |
| 2100 | yes | not by 400 | no |
Dates before the calendar reform are extrapolated
Today's Gregorian rules are applied to every year, including centuries before any country adopted them. For a date recorded under the Julian calendar the weekday here will not match the one written at the time.
Frequently asked questions
Does it handle past dates?
Yes, both past and future dates work.
How accurate is it?
It follows the Gregorian calendar, including leap year rules, so results are exact for any date the calendar covers.
What day of the week is 1 January 2026?
A Thursday. It is the date the field opens on, so pressing Calculate without changing anything returns that answer.
Does my time zone change the result?
No. The date is built from the year, month and day as typed, so the weekday is the same anywhere in the world.
Why is the date reformatted in the answer?
The result line rewrites the date through a formatter before the weekday name, so it may not look the way you typed it.