๐ Anniversary Calculator
Enter a start date to see the calculation
Enter the date you started dating or got married, and see how many days have passed, plus when milestone anniversaries like 100 days, 1 year, 500 days, or 1000 days fall. See your next upcoming milestone at a glance.
How to use
- Enter the starting date (when you started dating, your wedding date, etc.).
- The number of days elapsed and the nearest upcoming milestone are shown automatically.
- Browse the full milestone list to see both past and upcoming anniversaries.
How the calculation works
Enter the day you started dating, got married or any other start date to see which day today is and when milestones such as 100 days, 1000 days, 1 year and 10 years fall. Days are counted with the start date as day 1, the usual way of counting โdayโ anniversaries in Japan, so the 100-day anniversary is 99 days after the start. Yearly anniversaries fall on the same month and day. For a February 29 start date, the anniversary in common years is shown as February 28. The nearest milestone still to come is shown as the next milestone. Todayโs date comes from your device.
Worked example
Start date January 1, 2026 100 days: April 10, 2026 1000 days: September 26, 2028 1 year: January 1, 2027 10000 days: May 18, 2053 Starting on September 19, 2026, the 100-day anniversary is December 27, 2026.
Things to be aware of
- Some people count the day after the start as day 1. In that case, each date is one day later than shown here.
- Wedding anniversaries have traditional names by year, such as paper for the 1st, wood for the 5th, silver for the 25th and gold for the 50th.
- With a future start date, every milestone is shown as upcoming.
FAQ
How are the elapsed days counted?
The starting date counts as day 1 (so the day after is day 2), matching the common way milestone anniversaries are counted.
Can I use this for a wedding anniversary?
Yes โ set the starting date to your wedding date to see a list of upcoming wedding anniversaries.
What milestones does this cover?
Day-based milestones like 100, 200, 300, 500, 777, and 1000 days, plus year-based milestones like 1, 2, 3, 5, and 10 years.