Day of the Week Calculator

Find what day of the week any date falls on — past or future — plus day of the year and leap year.

What day of the week was I born?

Enter the date and the calculator shows the weekday along with the day of the year, ISO week, quarter, whether the year is a leap year, and how many days ago or from today the date is.

Leap years

A year is a leap year if it is divisible by 4, except years divisible by 100 unless they are also divisible by 400 — so 2000 and 2024 are leap years, but 1900 and 2100 are not.

Frequently asked questions

Does it work for old dates?

Yes, using the Gregorian calendar (dates before 1582 are calculated proleptically).

Can I check future dates?

Yes, any year.

Is it free?

Yes.