List of Leap Years

List Of Leap Years

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

(400 years × 365 common days) + (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 1600 (AD/CE) to 2100.