Yuan is the abbreviation of "Gregorian calendar era", which is a common chronological system in the world. Legend has it that Jesus was born in the first year of the Gregorian calendar. ?
This chronological system began to be adopted by European countries. China began to adopt the Gregorian calendar month and day (19 12) one year after the Revolution of 1911, but at the same time adopted the chronology of the Republic of China, and ancient China always used the lunar calendar. ?
The calendar year of People's Republic of China (PRC) adopts the calendar year system of most countries in the world, which was decided at the first plenary session of China People's Political Consultative Conference in September 1949. At the meeting, everyone agreed to adopt the common calendar system in most countries in the modern world, that is, adopt AD as the calendar year of new China.
On September 27th, the second of the four resolutions adopted at the first plenary session of the China People's Political Consultative Conference was: "The year number of People's Republic of China (PRC) adopts AD". ?
Extended data
1. In the western world, the year of birth of Jesus Christ was first used as a sign of time sequence. The time before the birth of Christ is called Before Christ in English, and the Chinese translation is "BC" or "BC"; The time after the birth of Christ (Latin) is called the year of Lord Minin (Jesus) in Arnaudeau, and Chinese translation is "A.D." or "A.D.".
Before Christ, it was generally abbreviated as B.C., and Anno Domini was generally abbreviated as A.D. For example:
In 44 BC
44 years before Christ literally means 44 years before the birth of Christ.
Ad 1066, ad 1066
The year of Anno Domini 1066 literally means the year of Christ 1066.
2. Algorithm
The Gregorian calendar is roughly the same as julian calendar, but the Gregorian calendar specifically stipulates that unless it is divisible by 400, all century years (divisible by 100) have no leap days;
Therefore, every 400 years, there are only 97 leap years in the Gregorian calendar, which is 3 leap years less than that in julian calendar. The average length of the Gregorian calendar is 365.2425 days, which is close to the average tropical year of 365.438+099074 days, that is, the error is about 3300 days, and it is also closer to the tropical year of the vernal equinox, that is, the error is about 8000 days.
In julian calendar, the Gregorian calendar year is 365.25 days, and the error is one day every 128 years. By 1582, the difference between the julian calendar vernal equinox (2 1 March) and the actual time of the earth's revolution to the vernal equinox is 10 day.
Therefore, when the Gregorian calendar was implemented, 1582, the day after 10, julian calendar was designated as Friday, 1582, 15, that is, 10 days were deleted, but the original cycle of the week remained unchanged.
Dionysius continued the Alexandria calendar and made a digital table called "Anne Domini Nostri Jesus Christ", which lasted for 95 years. The only reason why Dionysus invented the new 95-year form, which began in 532, was that in the year when he invented this form (525), there were still six years before the Cyrillic alphabet ended.
In other calendars, he did not say which year Jesus was born, but only calculated that it was 525 years since Jesus was born. He didn't realize that Easter in Alexandria was repeated every 532 years. Even though he obviously knew the 532-year cycle in the Victorian calendar, he just pointed out that Easter would not be repeated after 95 years.
He knew that the dates of Victoria Easter and Alexandria Easter were different, so he undoubtedly thought that the periods of the two calendars could not match. In addition, he obviously didn't realize that only 19×4×7( 19 period× leap year period× number of days per week) coincided with Alexander's 532-year period, otherwise he should have mentioned this simple fact.
Baidu Encyclopedia: AD.