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 epoch begins with the year one. 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 (without leap), 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 1/2 or 1/4 hours. There is 1 leap day every 4 years added to the second month, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leaps in 4 years.)
Burmese Kawza calendar	The epoch is possibly the year of the usurpation by the King Popa Sawrahan. The epoch begins with the year zero. There are 12 months (without leap) in a year. There are 29 (without leap) days in months of an odd number, 30 days in months of an even number. A month is divided into two parts: waxing and waning. The 15th day in a month is the day of full moon. The start of a day is at sunrise. There is 1 leap day added to the 3rd month. (There are about 1 leaps in 3 years.)
Chinese agricultural calendar	The epoch is the year of presumed enthronement of Yellow Thearch. The epoch begins with the year one. The start of a year is possibly the presumed day of enthronement of Thearch Shun. There are 12 (without leap) months in a year. The first month is the month with winter solstice. The first day of a month is the day with new moon. (There are 29 or 30 days in a month.) The start of a day is the midnight. The leap month is placed after 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 the world in Genesis. The epoch begins with the year one. The start of the year one is the presumed day of creation of the world in Genesis. There are 12 (without leap) months in a year. The start of a day is at sunset. There are 13 months for year 3, 6, 8, 11, 14, 17, 19 in a 19-year cycle. The leap month is placed at the end of the year. (There are about 7 leaps in 19 years.)
Japanese calendar	The epoch is the year of the reign of the current Emperor. The epoch begins with the year one. The start of the year one is the presumed day of circumcision of Jesus of Nazareth. There are 12 months in a year. Days for months are 31, 28 (without leap), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31. The start of a day is the midnight in Greenwich added by 9 hours. There is 1 leap day every 4 years added to the second month, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leaps in 4 years.)
Korean agricultural calendar	The epoch is the year of the foundation of Gojoseon. The epoch begins with the year one. The start of a year is possibly the presumed day of enthronement of Thearch Shun. There are 12 (without leap) months in a year. The first month is the month with winter solstice. The first day of a month is the day with new moon. (There are 29 or 30 days in a month.) The start of a day is the midnight. The leap month is placed after 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. The epoch begins with the year one. There are 12 months in a year. The first day of a month is the day with the first sight of the crescent. (There are 29 or 30 days in a month.) The start of a day is at sunset.
Republic of China calendar	The epoch is the year of presumed foundation of the Republic of China. The epoch begins with the year one. The start of the year one is the presumed day of circumcision of Jesus of Nazareth. There are 12 months in a year. Days for months are 31, 28 (without leap), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31. The start of a day is the midnight in Greenwich added by 8 hours. There is 1 leap day every 4 years added to the second month, except when the year is divisible by 100 and not divisible by 400. (There are about 1 leaps in 4 years.)
scheduled lunar Hijri calendar	The epoch is the year of Hijrah. The epoch begins with the year one. 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, 29 (without leap) days for the last month. There are 30 days in the last month, if the number of the year in a 30-year cycle multiplied by 11/30 minus the number of past leaps in the 30-year cycle is higher than 1/2. (Years with a leap in the 30-year cycle are 2, 5, 7, 10, 13, 16, 18, 21, 24, 26, 29.) The start of a day is at sunset. (There are 11 leaps in 30 years.)
solar Hijri calendar	The epoch is the year of Hijrah. The epoch begins with the year one. 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 (without leap) days in the last month. The start of a day is at sunset. (There are about 8 leaps in 33 years.)

Further reading: Is There a Perfect Calendar?

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.
Burmese timekeeping	A day is divided into 2 parts evenly. Every such part is divided into 4 units ‘ဗဟို’ evenly. Every ဗဟို is divided into 7.5 units ‘နာရီ’ evenly. Every နာရီ is divided into 4 units ‘ပါဒ်’ evenly. Every ပါဒ် is divided into 15 units ‘ဗီဇနာ’ evenly. Every ဗီဇနာ is divided into 6 units ‘ပြန်’ evenly. Every ပြန် is divided into 10 units ‘ခရာ’ evenly. Every ခရာ is divided into 12 units ‘ခဏ’ evenly. Every ခဏ is divided into 4 units ‘လယ’ evenly. Every လယ is divided into 1.25 units ‘အနုခရာ’ evenly.
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.