Anniversary Calculator
Years completed and days to the next anniversary.
Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.
Anniversary Calculator
How to use this tool
- Enter your values in the fields above.
- Press Generate. The result appears below the buttons.
- Use Load sample to see a worked example, or Clear to start again.
Worked example
From 15 June 2000 to 25 October 2026, 26 anniversaries have been completed, and the 27th falls on 15 June 2027, which is 233 days after 25 October 2026.
What this tool does not do / Limits
This counts whole calendar years between dates. It does not handle leap-day anniversaries beyond clamping 29 February to 28 February in non-leap years.
Frequently asked questions
What happens on the anniversary day itself?
That anniversary counts as completed, and the next anniversary shown is the following year's date.
Can I use any start date, not just a wedding?
Yes. It works for any recurring yearly date: a business opening, a work start date, or any other anniversary.
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