Does anyone know how to change the date and year in ancient history books?

Tiangan: A, B, C, D, E, Ji, G, Xin, Ren and Gui.

Dizhi: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai.

"Tiangan" and "Dizhi" are collectively called dry branches, and they are combined into 60 pairs in a certain way, which is a cycle, called 60 Jia Zi or 60 Hua Jia Zi. China was used to record years, months and days in ancient times.

In the lunar year, each earthly branch corresponds to 24 solar terms from one solar term (non-neutral) to the next, and the initial one-month cycle is determined by the node time, not from the first day to the end of a certain lunar month. Many almanac shows that a lunar month corresponds to a branch, which is only approximate but not complete. In case of a or one's own year, the first month is roughly C Yin; B or Geng Year, the first month is roughly Wuyin; The first month of year C or Xin is roughly Geng Yin, the first month of Ding Nian or Ren Year is roughly Ren Yin, and the first month of year E or decyl is roughly Jia Yin. The first month is calculated according to the main branch, and other months are calculated according to the main branch. A cycle of 60 months and 5 years; Reuse after a cycle, cycle after cycle, cycle. Winter to the sun and the moon (the month when heavy snow turns to slight cold, similar to November of the lunar calendar) is the "Jiaziyue" in the 29th year of Jianwu (AD 53). There is a song to prove it: the first year of A is C, and the first year of B is E; Bing Xin must find Geng, and Ding is downstream; What's more, there is no way to find it, and it is not bad to pursue good news. The following table shows the corresponding solar cycle, neutral atmosphere, approximate lunar month, approximate solar month, and monthly dry composed of annual dry and monthly dry:

Lunar solar terms are similar to lunar months, and solar months are similar to solar months A, B, C, D, E or D.

Beginning of spring, silver moon —— January, February, Bing Yin, Wu Yin, Geng Yin, Ren Yin and Jia Yin.

Uzuki startled-Qingming vernal equinox February March Ding Maoyue Ji Maoyue Xin Mao Gui Yue Uzuki Mao Yiyue

Qingming, Chen Yue-Grain Rain, long Xia San April Chen Wu Geng Yue Chen Yue Ren Chen Yue Chen Jia Yue Bing Chen Yue.

Long summer, Mitsuki-April, May, April, Xin, Gui, B, D, April.

Miscanthus in the afternoon-Summer solstice May June Geng Wu Ren Yue wuyue Wu Jia Yue Wu Bing wuyue wuyue

No Moon, Little Summer —— beginning of autumn, long summer, June, July, Wei Xingui, Yue Wei, B, Yue Wei, Ding Weiyue, less than a month.

Beginning of autumn, Shen Yue-Bailuyuan was appointed as Shenyue, Shen Jiayue, Shen Bingyue, Wu Shenyue and Geng Shenyue in July and August of the third day.

Wandering land-cold dew autumn equinox in August and September, Yue Yi swims Yue Yue.

Cold Dew on the Moon —— The first frost in beginning of winter in September 65438+ 10 Xu Jiayue Xu Bingyue Wuxu Month Geng Xuyue Ren Xuyue

Haiyue beginning of winter-Heavy snow and light snow 10 165438+ 10/0 Yihai Ding Yuehai Moon Ji Haiyue Xin Hai Gui Yue Hai Yue.

Heavy snow in the second month-slight cold winter solstice 1 1 month 65438+February Bing Zi Wu Yuezi Geng Yuezi Ren Yuezi Jia Ziyue.

The ugly moon

Slight Cold-beginning of spring Great Cold1Feb 65438+1Oct Ding Chou Yue Ji Chou Yue Xin Chou Gui Yue Chou Yue Yi Chou Yue.

The 60th day of a year is roughly a cycle of 2 months; Reuse after a cycle, cycle after cycle, cycle. According to the confirmed documents, the dates of trunks and branches began in February of the third year of the Lu Yingong summer calendar (February 65438 BC +00).

Because julian calendar has an average of 365 days in a year, once every four years, and the AD year is divisible by 4, and there are 366 days in leap years, with an average of 365.25 days in a year, the minimum common multiple of four years 146 1 day and 60 days in Jiazi is 29,220 days, that is, 80 years. That is to say, every 80 years, the date of julian calendar month and day corresponding to the anniversary of the main branch will be repeated. (AD 4 should have been a leap year, but after julian calendar implemented it in 45 BC, it was mistaken that leap days were added every three years, so the Roman emperor Octavian ordered that leap days should be stopped in the first five years, the previous 1 year and the fourth year to correct the mistakes. )

Because the Gregorian calendar has 365 days in a normal year, once every four years, the year of AD can be divisible by 100 but not by 400, and there are 366 days in a leap year, with an average of 365.2425 days in a year, so the minimum common multiple of 60 days in 400 146097 is 292 1940 days. That is to say, every 80 years, if the Gregorian calendar date corresponding to the branch date does not meet an AD year divisible by 100 but not by 400, the cycle will be repeated once. On the whole, assuming that the Gregorian calendar will never change in the future, the Gregorian calendar dates corresponding to the dates of trunks and branches will be repeated every 8000 years. 19 12 (the first year of the Republic of China), 18, the first day of the first lunar month, and 1992 are all "Jiazi Day".

Conversion between branch date and Gregorian calendar date

Calculate the Gregorian calendar year of the stem and branch from the known Gregorian calendar year: the number of years is reduced by 3, the remainder is divided by 10 for the heavenly stem, and the remainder is divided by 12 for the earthly branch.

The formula for calculating the branch date from the known date is:

g = 4c+(c/4)+5y+(y/4)+[3 *(m+ 1)/5]+d-3

z = 8c+(c/4)+5y+(y/4)+[3 *(m+ 1)/5]+d+7+I

Where i=0 in odd months, i=6 in even months, C is the number of centuries minus one, Y is the last two digits of the year, M is the month and D is the number of days. 65438+ 10 and February are calculated according to 65438+March and 65438+April of the previous year. [] means rounding. The remainder of g divided by 10 is heavenly stems, and the remainder of z divided by 12 is earthly branches.