Leap Year Calculator
Is it a leap year? This leap year calculator tells you right away whether February has 29 days in the year you enter. It shows the check by the rule (divisible by 4, 100 and 400), the previous and next leap year, the weekday of 29 February and the next twelve leap years.
Example: Year 2,028 → Result: 2028 is a leap year.. Source: Wikipedia – Leap year (Regel, 365,2425 Tage im Mittel, Schaltkinder). Updated: .
How it is calculated
A leap year has 366 days instead of 365 because February gets a 29th day. The Gregorian rule is: a year is a leap year if it is divisible by 4; if it is a century year, it must also be divisible by 400. So 2000 was a leap year, 1900 and 2100 are not, and 2024 and 2028 are.
Why is there a leap day?
The Earth needs about 365.2422 days to orbit the Sun, not exactly 365. Without correction the seasons would drift through the calendar. In 1582 Pope Gregory XIII refined the Julian rule (every 4th year): three leap days are dropped every 400 years, giving a mean year of 365.2425 days that is off by only about 26 seconds per year.
What the tool shows
- The check: the three divisibility tests and the rule that decides.
- Neighbours and list: the previous and next leap year and the next twelve. Usually four years lie between them, around 2100 it is eight.
- Weekday: the day on which 29 February falls, from the year 1583.
- Birthday on 29 February: people born on this day have a birthday on the real date only in leap years. Enter the birth year to count the real birthdays so far.
How many days lie between two dates, a leap day included, is worked out by the date calculator. The number of today within the year comes from the day of the year tool, and the exact age from a birth date from the age calculator.
Frequently asked questions
When is a year a leap year?
When the year is divisible by 4. Century years are the exception: they are leap years only if also divisible by 400. 2000 was a leap year, 2100 will not be.
When is the next leap year?
After 2024 it is 2028, then 2032 and 2036. The tool shows the next one for any year; just enter the current year.
Why is 1900 not a leap year?
1900 is divisible by 4 and by 100, but not by 400. Under the Gregorian rule the leap day is skipped in such century years; the same goes for 2100, 2200 and 2300.
How many days does a leap year have?
It has 366 days, a common year 365. February then has 29 days instead of 28.
How often do people born on 29 February have a birthday?
On the real date only every four years, in exceptional cases every eight. In other years it is usually celebrated on 28 February or 1 March; legally, one of the two applies depending on the country.
Sources and legal basis
- Wikipedia – Leap year (Regel, 365,2425 Tage im Mittel, Schaltkinder)
- Wikipedia – Gregorian calendar (Reform von 1582, Schaltregel)
As of: · Editorial policy
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