This is a list of calendar and timekeeping around the world.
Calendar
| name
|
description
|
| Gregorian calendar
|
- The year one is the year of presumed birth 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 and end of a day is the midnight at Greenwich added or subtracted by 1 or 1.5 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
- (97 leaps in 400 years)
|
| Chinese calendar
|
- The year one is the year of presumed birth of Jesus of Nazareth
- 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
- Leap month is the first month without a solar term of an even number
- (7 leaps in 19 years)
|
| Islamic calendar
|
- The year one is the year of Hijra
- There are 12 months in a year
- There are 29 or 30 days in a month, determined by the moon phase / There are 30 days in months of an odd number, 29 days in months of an even number
- The first day of a month is the day with the first sight of the crescent
- The start and end of a day is at sunset.
- Month with the leap day is the last month
- Year with the leap day is the year when the remainder is over half a day
- (11 leaps in 30 years)
|
Timekeeping
| name
|
description
|
| common timekeeping
|
- 1 day is divided by 12 units ‘hour’ evenly
- 1 hour is divided by 60 units ‘minute’ evenly
- 1 minute is divided by 60 units ‘second’ evenly
- 1 leap second is added to the last minute of a day irregularly
|
| Chinese timekeeping
|
- 1 day is divided by 12 units ‘時’ evenly
- 1 時 is divided into 2 parts: ‘初’, ‘正’ evenly
- Every 初 and 正 is divided by 4 units ‘刻’ evenly
|
