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

Calculation breakdown & reusable snapshots

WebToolArc mirrors the current inputs and visible result so you can copy or save a local snapshot without changing the calculator’s original controls.

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

Recent saved snapshots

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.

Repeat-use support

You can copy the current input/result summary or save up to five explicit snapshots locally in this browser.