Century leap year
Encyclopedia
In the Gregorian calendar
, an end-of-century leap year (often improperly referred to as a century leap year) is a year that is exactly divisible by 400 and, as with every other leap year
, qualifies for the intercalation
of February 29. End-of-century years that are exactly divisible by 4 but not by 400 are common year
s. The years 1200 (Extrapolated Gregorian Calendar
), 1600 and 2000, for example, were end-of-century leap years. The end-of-century years 1700, 1800, and 1900 were common years, as will be 2100, 2200 and 2300. The next end-of-century leap year will be 2400. End-of-century leap years always start on a Saturday
, and the resulting February 29 is always on a Tuesday
.
The end-of-century year "divisible by 400" rule of the Gregorian calendar was considered an improvement over the previously utilized Julian calendar
which had provided for a leap year at four year intervals. Over time, the Julian practice resulted in too many leap days being added to the calendar, thus causing it to gradually drift with respect to the astronomical seasons.
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...
, an end-of-century leap year (often improperly referred to as a century leap year) is a year that is exactly divisible by 400 and, as with every other leap year
Leap year
A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year...
, qualifies for the intercalation
Intercalation
Intercalation is the insertion of a leap day, week or month into some calendar years to make the calendar follow the seasons or moon phases. Lunisolar calendars may require intercalations of both days and months.- Solar calendars :...
of February 29. End-of-century years that are exactly divisible by 4 but not by 400 are common year
Common year
A common year is a common type of calendar year. It has exactly 365 days and so is not a leap year. More generally, it is a calendar year without intercalation....
s. The years 1200 (Extrapolated 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...
), 1600 and 2000, for example, were end-of-century leap years. The end-of-century years 1700, 1800, and 1900 were common years, as will be 2100, 2200 and 2300. The next end-of-century leap year will be 2400. End-of-century leap years always start on a Saturday
Saturday
Saturday is the day of the week following Friday and preceding Sunday.Saturday is the last day of the week on many calendars and in conventions that consider the week as beginning on Sunday, or the sixth day of the week according to international standard ISO 8601 which was first published in...
, and the resulting February 29 is always on a Tuesday
Tuesday
Tuesday is a day of the week occurring after Monday and before Wednesday.According to international standard ISO 8601, it is the second day of the week, although in some traditions it is the third....
.
The end-of-century year "divisible by 400" rule of the Gregorian calendar was considered an improvement over the previously utilized 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...
which had provided for a leap year at four year intervals. Over time, the Julian practice resulted in too many leap days being added to the calendar, thus causing it to gradually drift with respect to the astronomical seasons.