How it works
The next anniversary is the same month and day in the current year if it has not passed yet, otherwise next year. The anniversary number is the next date's year minus the original year. Leap-day (29 February) anniversaries fall on 1 March in non-leap years in this calculator, because JavaScript rolls the date forward — a quirk worth knowing if that is your date.
Frequently asked questions
What if today is the anniversary?
Then the countdown is 0 days and the number shown is this year's anniversary.