Anniversary Calculator

Enter a starting date and reference date to find completed yearly anniversaries, the next anniversary, weekday, and days remaining.

Starting date

Reference date

—Completed anniversaries

—Next anniversary number

—Days until next

—Next weekday

—Next yearly anniversary

Anniversary Calculator: Exact Time & Next Date

Show completed years, exact calendar duration, total days, next numbered anniversary and explicit February 29 handling.

Position quick-win audit

Feb 29 in non-leap years

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

Upcoming anniversary milestone schedule

Generate the next anniversaries from the same start/reference dates, including weekday and days-away values, so milestone planning does not stop at one next date.

Years to list

—Upcoming dates

—Next milestone

—Days away

Year #	Date	Weekday	Days away

Calendar or duration rule

The next anniversary reuses the month/day in the relevant calendar year and compares it with today.

Leap-day anniversaries can require a chosen convention in non-leap years.

Worked check

An anniversary is calendar-based, so the month and day matter more than dividing elapsed days by 365. Leap-day anniversaries are a special case because February 29 does not exist every year; verify how the returned next occurrence is handled for your purpose.

Rule: The next anniversary reuses the month/day in the relevant calendar year and compares it with today. Leap-day anniversaries can require a chosen convention in non-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.