To find the day of the week for any date, enter it in the day of the week calculator and read the weekday. It works for any past or future date and uses the real calendar, including leap years, so the answer matches the historical record.
If you would rather work it out yourself, or you need the Nth weekday of a month, here is how both work.
The quick way
A calculator is the fastest and most reliable method, because weekday maths is easy to get wrong by a day, especially across leap years and century boundaries. Type the date into the day of the week calculator and you have the answer.
It handles edge cases that catch people out, such as 29 February dates and years far in the past or future, where a quick mental estimate can drift.
Working it out in your head
If you enjoy the puzzle, there is a known mental method, sometimes called the Doomsday rule. The idea is that certain easy-to-remember dates in each year, such as 4 April, 6 June, 8 August, 10 October and 12 December, all fall on the same weekday, the year’s “anchor” day. Once you know that anchor, you count forward or back from the nearest anchor date to your target.
The method is reliable but takes practice, and a single slip puts you off by a day. For anything that matters, check the result against the day of the week calculator.
Finding the Nth weekday of a month
A related question is the reverse: not “what weekday is this date” but “what date is the third Monday of this month”. This comes up because many recurring events and holidays are defined by an occurrence rather than a fixed date.
To find it, list the dates of that weekday in the month and take the one you want, or use the calculator’s Nth-weekday mode. Pick the month and year, choose the weekday, and select first, second, third, fourth, fifth or last.
Watch for the fifth occurrence: not every month has five of a given weekday, so a fifth Friday sometimes does not exist. Choosing “last” always returns a real date.
Where this comes up
Knowing the weekday of a date is useful for:
- Trivia and history, such as which day a birthday or a historic event fell on.
- Recurring meetings, defined as the second Tuesday or last Friday of the month.
- Floating holidays, which are set as the Nth weekday of a month.
To group dates into numbered weeks instead, read what is an ISO week number, or open the day of the week calculator to try both modes.