2000 and 2100 follow different century rules
2000 is divisible by 400 and is a leap year. 2100 is divisible by 100 but not 400 and is a common year, with only 28 days in February.
Check one year
Divisible by 100 but not 400: the century exception applies.
365Days in year
28Days in February
2096Previous leap year (in range)
2104Next leap year (in range)
List leap years in a range
25 leap years across 101 years. Both endpoints are included.
2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036, 2040, 2044, 2048, 2052, 2056, 2060, 2064, 2068, 2072, 2076, 2080, 2084, 2088, 2092, 2096
The proleptic Gregorian rule is applied to years 1–9999. Historical adoption dates and Julian leap years are not modeled.
Calculations run in your browser. Dates and settings are not uploaded by this tool.
How to use the Leap Year Calculator
- 01
Enter a year from 1 through 9999. The result shows leap or common year and explains the divisibility rule.
- 02
Check February’s length, the total days in the year, and the previous and next leap year within the supported range.
- 03
For a list, enter an inclusive start and end year. Review the count and copy the comma-separated results.
Examples
A gap of eight years
An inclusive range from 2096 through 2104 contains the leap years 2096 and 2104. The skipped century leap day means the gap around 2100 is eight years rather than four.
The Gregorian divisibility test
A year normally gains February 29 when divisible by four. Years divisible by 100 are exceptions, unless they are also divisible by 400. Applying the tests in this order explains why a simple every-four-years rule fails at several century boundaries. The calculator reports the rule that decided the result.
A year check and a range list answer different questions
The single-year panel identifies the selected year and its nearest earlier and later leap years. Neighboring years exclude the selected year itself, even if it is leap. The range panel includes both endpoints, removes no years, and reports a total that can be checked against the displayed list. Reversing the range is an input error rather than a request to reorder it.
Historical calendars need a separate assumption
This tool extends the Gregorian calendar rule backward through year 1. That is useful for consistent date arithmetic, but does not mean every country used those dates historically. A date from a Julian-calendar source can obey a different leap-year rule, and national calendar reforms omitted dates at different times. The result here is a Gregorian classification only.
Common questions
Is every fourth year a leap year?
The century exceptions matter: 1900 and 2100 are not leap years, while 2000 is. Use the full divisibility test rather than only checking division by four.
Does a leap year have 366 days?
Yes, under this calendar rule it has 366 dates, including February 29. A common year has 365.
Why can a neighboring leap year say None?
The search is restricted to years 1–9999. Near the endpoints, no earlier or later leap year may exist within the supported interval.