Weekday Calculator

Choose a date to instantly see whether it falls on Monday, Tuesday, or another weekday.

Date

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Core timing workflows

Start with a direct timer, stopwatch, alarm or focus workflow. Calendar, date arithmetic, clocks and scheduling specialists remain available from the full Date & Time hub.

All 76 date & time tools

Online TimerCountdown, sound, repeat & fullscreen StopwatchLaps, precision & fullscreen Countdown TimerFocused countdown workflow Alarm ClockAlarm at a local clock time PomodoroFocus and break cycles Interval TimerWork/rest rounds Presentation TimerTalk timing with warnings Classroom TimerProjector-friendly countdown

Weekday, ordinal day & ISO week evidence

Resolve a date to weekday and expose ordinal day, ISO week/year and an offset-date check in one result.

DateOffset days

—Weekday

—Day of year

—ISO week

—Offset date

Ready.

Calendar or duration rule

The weekday is derived from the selected Gregorian calendar date.

For historical/legal calendar questions, local calendar adoption can differ by country.

Worked check

A good reference check is January 1, 2000, which was a Saturday in the Gregorian calendar. If a historical date is being researched, remember that local adoption of the Gregorian calendar did not happen everywhere on the same date.

Rule: The weekday is derived from the selected Gregorian calendar date. For historical/legal calendar questions, local calendar adoption can differ by country. For a final check, distinguish calendar arithmetic from elapsed duration, confirm the intended local date or time zone, and inspect month-end, leap-year or daylight-saving boundaries when they can affect the meaning.

Date-only weekday semantics

The weekday is derived from the selected Gregorian calendar date, independent of the browser’s current clock time or daylight-saving transition.