the Gregorian calendar is a universal calendar in the world. The Gregorian calendar is also called the Gregorian calendar in China. The digital date on the calendar is the Gregorian calendar. So who invented the Gregorian calendar? How did the Gregorian calendar come from? Presumably, many people do not understand the origin of the Gregorian calendar. This article brings you the historical origin of the Gregorian calendar. Let's learn about the Gregorian calendar, which is indispensable in our daily life.
Historical origin of the Gregorian calendar
The predecessor of the Gregorian calendar is the Julian calendar revised by Caesar in ancient Rome.
According to the provisions of the Julian calendar, there is a leap year every four years, with 366 days in leap years and 365 days in the other three years (called ordinary years). Leap years are divisible by 4.
The Julian calendar has an average length of 365.25 days a year, 11 minutes and 14 seconds longer than 365.2422 days of the actual revolution cycle, that is, about 3 days every 400 years.
Thus, by the 16th century, it had accumulated 10 days of error. You can obviously feel that two or two points are ahead of schedule.
In this case, Pope Gregory XIII announced the change of calendar in 1582.
First, the next day on October 4 of the Julian calendar in 1582 was set as October 15 of the Gregorian calendar, and 10 days were skipped in the middle.
At the same time, the leap rule of the Julian calendar is modified. Except that the number of Julian calendar years divided by 4 is leap year.
Added the rule that leap years are not leap years that can be divided by 100 but not 400.
This approach can reduce three leap years in 400 years. In the Gregorian calendar, there are 97 leap years (366 days a year) and 303 ordinary years (365 days a year) in 400 years, so the average annual length is 365.2425 days, which is very close to 365.2422 days of the revolution cycle.
It can be basically guaranteed that the error will not exceed 1 day before 5000 ad.