Days in Month Calculator

Choose a month and year to get its exact day count.

Month

Year

—Days in month

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

Month boundaries, weekdays & mini calendar

Show the Gregorian month length together with first/last weekday and a compact calendar grid for the selected month.

YearMonth (1–12)

—Days

—First weekday

—Last weekday

—Calendar rows

Ready.

Calendar or duration rule

Month length follows Gregorian calendar rules for the selected year.

February has 29 days only in leap years.

Worked check

February is the useful edge case: it has 28 days in an ordinary year and 29 in a leap year. April, June, September and November have 30; the remaining ordinary months have 31.

Rule: Month length follows Gregorian calendar rules for the selected year. February has 29 days only in leap years. 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.

Gregorian month length

February is 29 days in years divisible by 4, except century years unless divisible by 400. Other month lengths are fixed by the Gregorian calendar.