Day of the Week Calculator

Find out which day of the week any date falls on.

Your result will appear here

Fill in the fields and press Calculate.

What day of the week were you born? What day does a future date land on? Working it out by hand means tracking leap years and month lengths across centuries — easy to get wrong. This tool tells you the weekday for any date, past or future, in an instant.

Enter a date, and its day of the week appears immediately.

How is it calculated?

How it's found

Every date corresponds to a fixed position in the seven-day cycle, calculated from a known reference point with leap years and month lengths accounted for. The tool handles the arithmetic that makes hand methods (like Zeller's congruence or the "doomsday" rule) error-prone.

Why it's not obvious

The weekday of a date shifts by more than one each year because 365 ÷ 7 leaves a remainder of 1 — and 2 in leap years. So the same calendar date lands on a different weekday from year to year, and the pattern only repeats every 28 years (in the Gregorian calendar, with exceptions around century years).

Common uses

  • Birthdays: the weekday you were born, or when your birthday falls this year.
  • Planning: what day a future deadline, event or holiday lands on.
  • History: the weekday of a historical date.
  • Scheduling: checking whether a date is a weekend.

For counting days to or from a date, a days-until-date or days-since-date calculator is the companion tool.

Worked example

Enter 15 March 1990 and the tool returns Thursday — the weekday that date fell on. For a reference point many people know, 1 January 2000 was a Saturday. Notice that the same date one year later usually shifts by one weekday (and by two across a leap year), which is exactly why you can't just assume "my birthday is on the same day every year" — it moves, and the tool tracks that movement precisely.

FAQ

How do I find the day of the week for a date?+

Just enter the date — the tool calculates its position in the seven-day cycle, accounting for leap years and month lengths, and returns the weekday.

Can it find the day for a future date?+

Yes — it works for any date, past or future. Enter a future date to see which weekday a deadline, event or holiday will fall on.

Why doesn't my birthday fall on the same weekday each year?+

Because 365 days is 52 weeks plus 1 day (2 in a leap year), so a date shifts forward by one or two weekdays each year. The full pattern repeats only every 28 years.

What day of the week was I born?+

Enter your date of birth and the tool returns the exact weekday — for example, 15 March 1990 was a Thursday.

How does the tool handle leap years?+

Leap days (29 February) are included in the calculation, which is why the weekday shifts by two rather than one across a leap year. The result is always exact.

Does it work for very old historical dates?+

It works within the Gregorian calendar. For dates before its adoption (which varied by country), historical weekdays can differ due to the earlier Julian calendar.