Language/Multiple-languages/Culture/Calendars-and-Clocks

This is a list of calendar and timekeeping around the world.

Calendar

name	description
Gregorian calendar	The epoch is the year of presumed birth of Jesus of Nazareth. The start of a year is the presumed day of circumcision of Jesus of Nazareth. There are 12 months in a year. Days for months are 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31. The start of a day is the midnight in Greenwich added or subtracted by multiples of 1 hour, and in some cases further adding or subtracting 0.5 or 0.25 hours. The leap day is placed in the second month. There is 1 leap day every 4 years, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leap in 4 years.)
Chinese agricultural calendar	The epoch is the year of presumed enthronement of Yellow Thearch. The start of a year is possibly the presumed day of enthronement of Thearch Shun. There are 12 or 13 months in a year. The first month is the month with winter solstice. There are 29 or 30 days in a month, determined by the moon phase. The first day of a month is the day with new moon. The start of a day is the midnight. Leap month is the first month without a solar term of an even number. (There are about 7 leaps in 19 years.)
Hebrew calendar	The epoch is the creation of world in Genesis. There are 12 or 13 months in a year. (There are 7 leaps in 19 years.)
Japanese calendar	The epoch is the year of the reign of the current Emperor. The start of a year is year is the presumed day of circumcision of Jesus of Nazareth. There are 12 months in a year. Days for months are 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31. The start of a day is the midnight in Greenwich added by 9 hours. The leap day is placed in the second month. There is 1 leap day every 4 years, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leap in 4 years.)
Korean agricultural calendar	The epoch is the year of the foundation of Gojoseon. The start of a year is possibly the presumed day of enthronement of Thearch Shun. There are 12 or 13 months in a year. The first month is the month with winter solstice. There are 29 or 30 days in a month, determined by the moon phase. The first day of a month is the day with new moon. The start of a day is the midnight. Leap month is the first month without a solar term of an even number. (There are about 7 leaps in 19 years.)
lunar Hijri calendar	The epoch is the year of Hijrah. There are 12 months in a year. There are 29 or 30 days in a month, determined by the moon phase. The first day of a month is the day with the first sight of the crescent. The start of a day is at sunset.
Republic of China calendar	The epoch is the year of presumed birth of the foundation of the Republic of China. The start of a year is year is the presumed day of circumcision of Jesus of Nazareth. There are 12 months in a year. Days for months are 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31. The start of a day is the midnight in Greenwich added by 8 hours. The leap day is placed in the second month. There is 1 leap day every 4 years, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leap in 4 years.)
scheduled lunar Hijri calendar	The epoch is the year of Hijrah. There are 12 months in a year. There are 30 days in months of an odd number, 29 days in months of an even number. The leap day is added to the last month. The start of a day is at sunset. (There are about 11 leaps in 30 years.)
solar Hijri calendar	The epoch is the year of Hijrah. The start of a year is the vernal equinox. There are 12 months in a year. There are 31 days in the first 6 months, 30 days in the next 5 months, 29 days in the last month. The start of a day is at sunset. The leap day is added to the last month. (There are about 8 leaps in 33 years.)

Timekeeping

name	description
European timekeeping	A day is divided by 12 units ‘hour’ (in English) evenly. An hour is divided by 60 units ‘minute’ (in English) evenly. A minute is divided by 60 units ‘second’ (in English) evenly. A leap second is added to the last minute of a day irregularly.
Chinese timekeeping	A day is divided by 12 units ‘時’ evenly. A 時 is divided into 2 parts: ‘初’, ‘正’ evenly. Every such part is divided by 4 units ‘刻’ evenly.
Thai timekeeping	A day is divided by 4 periods ‘...โมงเช้า’, ‘บ่าย...โมง’, ‘...ทุ่ม’, ‘ตี...’ evenly. Every such period is divided into 6 parts evenly.