A leap year has 366 days, one extra day (Feb. 29) over a normal year. Nearly every 4 years is a leap year (97 leap years out of every 400 years).

Is it a leap year? Last leap year before & next leap year after this year

The leap year algorithm. The three conditions to check in order to know whether a year is a leap or a common one:

1) A leap year can be evenly divided by 4

2) Except if it can be evenly divided by 100 then it isn't a leap year

3) Except if it can be evenly divided by 400, then it's a leap year

Latest checked up years / leap or common years?

Is 1653 a leap year? When is the last leap year before 1653? When is the next leap year after 1653? Dec 15 03:02 UTC (GMT)
Is 1641 a leap year? When is the last leap year before 1641? When is the next leap year after 1641? Dec 15 03:02 UTC (GMT)
Is 1640 a leap year? When is the last leap year before 1640? When is the next leap year after 1640? Dec 15 03:02 UTC (GMT)
Is 1623 a leap year? When is the last leap year before 1623? When is the next leap year after 1623? Dec 15 03:02 UTC (GMT)
Is 1678 a leap year? When is the last leap year before 1678? When is the next leap year after 1678? Dec 15 03:02 UTC (GMT)
Is 1666 a leap year? When is the last leap year before 1666? When is the next leap year after 1666? Dec 15 03:02 UTC (GMT)
Is 1653 a leap year? When is the last leap year before 1653? When is the next leap year after 1653? Dec 15 03:02 UTC (GMT)
Is 1660 a leap year? When is the last leap year before 1660? When is the next leap year after 1660? Dec 15 03:02 UTC (GMT)
Is 1689 a leap year? When is the last leap year before 1689? When is the next leap year after 1689? Dec 15 03:02 UTC (GMT)
Is 1691 a leap year? When is the last leap year before 1691? When is the next leap year after 1691? Dec 15 03:02 UTC (GMT)
Is 1796 a leap year? When is the last leap year before 1796? When is the next leap year after 1796? Dec 15 03:02 UTC (GMT)
Is 1946 a leap year? When is the last leap year before 1946? When is the next leap year after 1946? Dec 15 03:02 UTC (GMT)
Is 1583 a leap year? When is the last leap year before 1583? When is the next leap year after 1583? Dec 15 03:02 UTC (GMT)
All users checked up years / leap or common

Leap Years. Common Years. What are they and why do we need them? Leap years algorithm.

What is a leap year? What is a common year?

A leap year contains 1 extra day, February 29th, over an ordinary year, 366 vs. 365.

How often do the leap years occur in the calendar?

Nearly once every four years, 97 leap years at every 400 years.

Why do we need leap years?

They keep the calendar year synchronized with the astronomical year, preventing us, for example, from celebrating Christmas in November.

Leap years algorithm.

Every year that is evenly divisible by 4 is a leap year, except for years that are evenly divisible by 100, but these years are leap years if they are evenly divisible by 400:

Examples of leap years.

  • Leap years multiples of 4 but not of 100 nor of 400: 1992, 1996, 2004, 2008, 2012, 2016, 2020, 2024, 2028;
  • Common years (NOT LEAP YEARS) multiples of 100, but not of 400: 1700, 1800, 1900, 2100, 2200, 2300;
  • Leap years multiples of 400: 1600, 2000, 2400.

What is a leap year? What is a common year?

How often do the leap years occur in the calendar?

Why do we need leap years?

Leap years algorithm. Examples.

When did the leap year originate?

The modern (Gregorian) calendar and the Julian one. Julian calendar adjustment

How accurate is the Gregorian calendar, based on the leap year algorithm?


See all the articles about leap years above grouped together as a single article.


List of all the leap years between 1582 and 4818.