ShadTools

Leap Year Checker

Check whether any year is a leap year and review the exact Gregorian leap-year rules.

Is 2024 a leap year?
Yes (Leap Year)
366 daysdays in year
2024 is a leap year because it is divisible by 4 and is not a century year.explanation

Check whether any year in the Gregorian calendar is a leap year with 366 days.

Gregorian Calendar Rule

  1. Rule 1: If the year is evenly divisible by 4, it is a leap year candidate.
  2. Rule 2: If the year is also divisible by 100 (century year), it is NOT a leap year…
  3. Rule 3: …UNLESS the year is also divisible by 400, in which case it IS a leap year.

Examples

  • 2024: Divisible by 4 $\rightarrow$ Leap Year (366 days)
  • 1900: Century year (divisible by 100) but not 400 $\rightarrow$ Not a Leap Year (365 days)
  • 2000: Century year divisible by 400 $\rightarrow$ Leap Year (366 days)

Frequently Asked Questions

What is the Gregorian leap year rule?+

A year is a leap year if it is divisible by 4, EXCEPT century years (divisible by 100) which are NOT leap years UNLESS they are also divisible by 400.

Why was the 400-year rule created?+

A solar year is approximately 365.2422 days. Adding a leap day every 4 years (365.25 days) slightly overcorrects time over centuries. Skipping 3 century leap years every 400 years maintains long-term astronomical alignment.

How many days are in a leap year?+

A leap year has 366 days instead of the usual 365 days, adding February 29th to the calendar.

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