Day of the Week Calculator

The day of the week calculator tells you which weekday any date falls on — past, present, or future. Choose a date and it instantly returns the day, from Monday through Sunday, along with whether that date is a working day or falls on the weekend.

This is more useful than it first sounds. Planning an event, checking when a deadline lands, settling a friendly argument about the day of a wedding, or working out which dates in a month are Saturdays all come down to knowing the weekday for one specific date. Because the calculator works for any year, you can look decades into the past or plan far into the future without reaching for a physical calendar.

Under the hood it uses the Gregorian calendar, the system in everyday civil use around the world. Dates are handled in a timezone-safe way, so a date always returns the same weekday no matter where you are or when you check. Leap years are accounted for automatically, which matters for dates late in a leap year where a careless calculation can drift by a day.

To use it, pick your date and press Find the day. The weekday appears immediately, with no page reload, and a short note tells you whether it is a weekday or part of the weekend. Impossible dates are rejected with a clear message rather than a wrong answer.

Common uses include confirming the weekday of a historical event, scheduling recurring meetings, checking whether an official deadline lands on a weekend — which often pushes it to the next working day — and planning travel or delivery windows.

Every date maps to a day-of-week number from 0 (Sunday) to 6 (Saturday). The calculator anchors the date at midnight UTC and reads its weekday from the calendar, so the result never shifts with your local timezone. Because the Gregorian calendar repeats on a 400-year cycle, the same rules apply to any year you enter.