Leap Year Checker
Online leap year checker validates single years and ranges, showing rule reasons, year days, and February days for date calculations, scheduling checks, and fiscal period validation.
Leap Year Checker
Reason
Year 2026 is
Common Year
Days in Year
365 days
Days in February
28 days
Reason
Not divisible by 4, so it is a common year
Leap Year Rules
Leap year checker follows Gregorian calendar logic and is useful for date math, scheduling, fiscal cycles, and system time validation.
Gregorian Rules
- A year divisible by 4 and not divisible by 100 is a leap year.
- A century year divisible by 400 is also a leap year.
- All other years are common years.
Typical Examples
- 2000: leap year (divisible by 400)
- 1900: common year (divisible by 100 but not by 400)
- 2024: leap year (divisible by 4 but not by 100)
- 2023: common year (not divisible by 4)
Why Leap Years Exist
Earth's orbital cycle is about 365.2422 days. If a calendar always used 365 days, timing would drift over years. Leap years keep calendar dates aligned with astronomy.