How to use the anniversary alert date calculator
Enter the month and day of the anniversary, how many days of warning you want, and how many years to list, and the page builds a table of each year's anniversary date and weekday alongside the alert date and its weekday, then reports how many days are left until the next alert. It suits anything that returns on the same date every year, such as a wedding anniversary, a memorial or an insurance renewal, because the warning is planned with it. A 29 February date lets you choose the common-year rule yourself.
How the numbers are produced
Every date is built from coordinated universal time components and each weekday is read from the same value, so the results match in any time zone. Leap years follow the Gregorian rule, divisible by 4 and, when divisible by 100, only if also divisible by 400, and the alert date is the anniversary minus the lead days. Figures are as of October 2026.
Limits and what is not covered
Anniversaries that repeat on a day-count interval, such as every 100 or 1,000 days, are not covered. Lunar-calendar anniversaries fall on a different solar date each year and are not converted, and the page neither sends real notifications nor exports to a calendar app.
Frequently asked questions
You can pull it back to 28 February, push it to 1 March, or skip that year, and the rule applied is printed on the first result line. Leap years follow the Gregorian rule: divisible by 4, and when divisible by 100 only if also divisible by 400.
A long lead time can place the alert for the coming anniversary before the reference date. The page then reports how many days ago the alert fell instead of a countdown, so you can see that preparation is already due.
Yes. The table lists the weekday of each anniversary and of each alert date, so you can spot the years that land on a weekend well in advance when arranging a gathering or adding leave around it.