How to calculate the months and hours of the heavenly stems and earthly branches

1. Method for calculating the stems and branches of AD: Note that the stems and branches of the first year of AD here only represent the period between the beginning of spring in the first year of AD (around February 4) and the beginning of spring in the next AD year (around February 4). The return year stems and branches. For example: the Yiwei year of 2015 is expressed (February 4, 2015 - February 4, 2016).

2. Ordinal number method:

The ordinal number of the heavenly stems is: 1 (A), 2 (B), 3 (C), 4 (D), 5 (E), 6 ( Ji), 7 (Geng), 8 (Xin), 9 (Ren), 10 (Gui)

The order of the earthly branches: 1 (Yin), 2 (Mao), 3 (Chen), 4 ( Si), 5 (noon), 6 (wei), 7 (Shen), 8 (unit), 9 (Xu), 10 (Hai), 11 (Zi), 12 (Chou)

3 . Year calculation method:

Since the heavenly stems and earthly branches cycle every 60 years, the corresponding year values ​​cannot be calculated directly based on the stems and branches. However, we can calculate the corresponding year in 60 years based on the stems and branches, so as to make further calculations.

Suppose x is the corresponding order of the heavenly stems, Jia-Gui is 1-10; y is the corresponding order of the earthly branches, Zi-Hai is 1-12. Then the calculation formula of the corresponding order z is: z = 6x - 5y, if negative, add 60.

The calculation is based on the congruence equation: z≡x (mod 10), z≡y (mod 12), x≡y (mod 2), and the solution is z≡36x+25y (mod 60) , which can be obtained by further simplification.

Many historical events in modern Chinese history are named based on the chronology of the Heavenly Stems and Earthly Branches, such as: the Xinyou Coup in 1861, the Sino-Japanese War of 1894 in 1894, the Reform Movement of 1898 in 1898, and the Treaty of Xinyou in 1898. In 1901, the Revolution of 1911 happened in 1911, and the Renzi Guichou academic system was promulgated in 1912-1913.

Extended information:

1. The composition of the heavenly stems:

The five elements of the heavenly stems are divided into yin and yang, specifically: Jia wood, Yi wood, Bing fire, Ding Fire, Wutu, Jitu, Gengjin, Xinjin, Renshui, Guishui, among which Jia, Bing, Wu, Gengren and Yi are positive, Yi, Ding, Ji, Xin and Gui are negative.

In the Chinese calendar, A, B, B, Ding, Wu, Ji, Geng, Xin, Ren, and Gui are called the "Ten Heavenly Stems", while Zi, Chou, Yin, Mao, Chen, and Si , Wu, Wei, Shen, You, Xu and Hai are called the "Twelve Earthly Branches".

2. The composition of the Earthly Branches:

Earthly Branches: Zi (zǐ), Chou (chǒu), Yin (yín), Mao (mǎo), Chen (chén), Si (sì) ), Wu(wǔ), Wei(wèi), Shen(shēn), You(yǒu), Xu(xū), and Hai(hài). Also called twelve branches.

In ancient China, the twelve earthly branches were used to track time and months. The earthly branch time is to divide a day into 12 periods, which are represented by the twelve earthly branches. Zi hour is from 23 to 1 o'clock, Chou hour is from 1 to 3 o'clock, etc., which are called twelve hours. According to the earthly branch calendar, the month in which the winter solstice occurs is called the Zi month, the next month is called the Chou month, and so on.

Baidu Encyclopedia-Heavenly Stems and Earthly Branches

Baidu Encyclopedia-Heavenly Stems

Baidu Encyclopedia-Earthly Branches