Leap year check
Yes, 4000 is a leap year.
4000 is divisible by 400, so it overrides the "century is not a leap year" exception and IS a leap year.
A year is a leap year in the Gregorian calendar when it is divisible by 4, with one exception and one exception to that exception: a year divisible by 100 is not a leap year unless it is also divisible by 400. 4000 is a century year, but because it is also divisible by 400 (4000 ÷ 400 = 10), the century exception is overridden and 4000 is a leap year. These are the rarest leap years, only one century in four qualifies.
Because 4000 is a leap year, it has a February 29, and that date falls on a Tuesday. Anyone born on this date is a "leapling" whose true calendar birthday only comes around every four years. Every date from March 1 4000 onward sits one weekday later than it would in a common year, a quiet side effect of the extra day.
4000 runs 366 days, or 52 full weeks plus 2 days. The leap year before 4000 was 3996 and the next one is 4004, keeping the familiar four-year rhythm. To do date math across 4000, counting days to a deadline, an age, or an anniversary that crosses the leap day, use the days-between calculator, which handles leap days automatically.
Check another year
Type a different year, or count the leap years across a range.
Enter any year from 1582 to 4000.
Yes, 4000 is a leap year
4000 is divisible by 400, so it overrides the "century is not a leap year" exception and IS a leap year.
Count leap years in a range
How many leap years fall between two years (inclusive).
Enter a valid from/to range within 1582-4000.