Worked example. Change the dates to calculate your own.
February has 29 days.
- Days in the year
- 366
- Calendar
- Gregorian
A year is leap if divisible by four, except century years must also be divisible by 400. Uses the Gregorian calendar.
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How this calculation works
A Gregorian year is a leap year if it is divisible by four, except century years must also be divisible by 400. So 2000 is a leap year and 2100 is not. Enter a whole year from 1000 through 9999.
A worked example
2028 is divisible by four and is not a century year, so it is leap. 2100 is divisible by 100 but not 400, so it is not leap. 2000 is divisible by 400, so it is leap. Leap years have 366 days.
Check the century exception explicitly
Divisibility by four alone is not enough for Gregorian century years.
| Year | Gregorian result |
|---|---|
| 1900 | Not leap. Divisible by 100 but not 400. |
| 2000 | Leap. Divisible by 400. |
| 2028 | Leap. Divisible by 4 and not a century. |
| 2100 | Not leap. Divisible by 100 but not 400. |
Enter the year
Enter a whole year from 1000 through 9999 and Calculate. For a February 29 birthday, choose your celebration rule in the next-birthday calculator.
Plan your leap-day birthday countdown
Planning a February 29 birthday? Keep the original birthday in Daymark and add a separate countdown for your chosen celebration date.
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