Leap Year Checker
Check whether years are leap years, and see the rule that decided it.
Good to know
How should I write a date?
Use year-month-day, such as 2026-09-05, to avoid confusing the day and month.
What does a blank comparison date mean?
The comparison uses today when its second date is empty.
Are the years and months exact?
The years-and-months breakdown is approximate. Use the elapsed whole days, hours or minutes when you need a duration.