In the Gregorian calendar

Gregorian calendar

The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...

, the current standard calendar in most of the world, most years that are divisible by 4 are leap years

Leap Years

Leap Years is a 2001 drama television series that aired on the Showtime cable network. The show was created by Ron Cowen and Daniel Lipman, who had created the American version of the series Queer as Folk. It followed a group of friends in New York City...

. In a leap year, the month of February has 29 days instead of 28. This compensates for the fact that a solar year is about 6 hours longer than 365 days, by adding an extra day (a leap day) to the calendar every four years.

However, the duration of a solar year is approximately 365.2422 days, slightly less than 365.25 days. The old rule of adding a leap day every fourth year overcompensates. The Gregorian calendar therefore adjusts the leap year rule by omitting three leap days every 400 years, turning three years that would be leap years in the older Julian calendar

Julian calendar

The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...

 into common years. This leads to an average calendar year of 365.2425 days, which is very close to the length of the solar year:
+ (100 − 3) leap days = 146097 days in 400 Gregorian years.

146097 days ÷ 400 years = 365.2425 days per Gregorian year

Each 400-year period has four century years (years divisible by 100), but only one of those is divisible by 400. The century years not divisible by 400 are identified by the Gregorian calendar as the three years in which the usual leap day is omitted. For example, 1600 and 2000 were leap years, but 1700, 1800 and 1900 were not. Future century years 2100, 2200, 2300, 2500, 2600, 2700, 2900, and 3000 will not be leap years, but 2400 and 2800 will be.

By this rule, the average number of days per year is 365 + 1/4 − 1/100 + 1/400 = 365.2425.

What follows is a list of all leap years from the year 1600 (AD/CE

Common Era

Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...

) to 2108.

1600
1604
1608
1612
1616
1620
1624
1628
1632
1636
1640
1644
1648
1652
1656
1660
1664
1668
1672
1676
1680
1684
1688
1692
1696

1704
1708
1712
1716
1720
1724
1728
1732
1736
1740
1744
1748
1752
1756
1760
1764
1768
1772
1776
1780
1784
1788
1792
1796

1804
1808
1812
1816
1820
1824
1828
1832
1836
1840
1844
1848
1852
1856
1860
1864
1868
1872
1876
1880
1884
1888
1892
1896

1904
1908
1912
1916
1920
1924
1928
1932
1936
1940
1944
1948
1952
1956
1960
1964
1968
1972
1976
1980
1984
1988
1992
1996
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

2104
2108