The Heavenly Stems and Earthly Branches are our ancient chronological method. Just like the AD chronological method we use now, how do we calculate the Heavenly Stems and Earthly Branches? Does it mean it is converted into the Age?
As the name suggests, the heavenly stems and earthly branches are the stems and branches of trees. There are ten heavenly stems: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren and Gui; the twelve earthly branches: Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai.
1. The formula for calculating the years after AD of the stems and branches is:
"The number of years in the first year is reduced by three. The number of more than 10 is the heavenly stems. The base is used to divide by 12, and the remainder is the year of the earthly branch."
Taking 2010 as an example, subtracting 3 from the year to get the base 2007, dividing by 10 to get the remainder 7, and checking the order of the heavenly stems (A, Yi, B, Ding, Wu, Yi, Geng, Xin, Ren, Gui).
Get "Geng", then divide the base 2007 by 12 to get the remainder as 3, and then check the order of the earthly branches (Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai) and get "Yin", so 2010 is the year of Geng Yin. (If you get 0, it can be understood as 1 before 1, that is, 12)
2. The earthly branches of the month stems and branches are fixed, such as Yin starting from the first month, and only the month stems are calculated.
Month stem = year stem number multiplied by 2+month example: The heavenly stem of the three month (Chen month) in 2010 (Gengyin) = 7*2+3=17. The 10 heavenly stem is a cycle, so remove 10 and get 7. The 7th position of the heavenly stem is Geng, then this month stem and branch is Gengchen.
3. Day stem and branch 1900-1999 day stem and branch base = (two digits at the end of the year + 3)*5+55+ (two digits at the end of the year - 1) Dividing 42000-2099 day stem and branch base = (two digits at the end of the year + 7)*5+15+ (two digits at the end of the year + 19) Dividing 4 (only use the quotient, no remainder, if you count 60, remove 60)
Example: The number of stems and branches on Monday, April 12, 2010 = (10+7)*5+15+(10+19)/4=47 (multiple of 60 has been removed) This is the number of stems and branches on January 1. From January 1 to April 12, it is 47+31 (January days, and so on) + 28+31+12=149. Remove the multiples of 60 and get 29. The multiples of the heavenly stems are 10 and the remaining 9 is Ren, and the multiples of the earthly branches are 12 and the remaining 5 is Chen. Today's stems are Ren Chen.
4. Hour stems and branches hour stems = day stems number *2 + day branches number -2
5. The method of reverse-reducing age deduces stems and branches of any age from this year's stems and branches, that is, age deletion 60 as the base, remove multiples of 10 as the inverse deduction number of the heavenly stems, and remove multiples of 12 as the inverse deduction number of the earthly branches.
This year is the year of Geng Yin, and the stems and branches of the 56th year of birth are like this: 56 is more than 50, the heavenly stems are reversed from Geng and are Yi, and the earthly branches are 56 are removed more than 488, and the 8th position is reversed from Yin and are Wei, and the birth year is Yi Wei. The birth year of 65 is removed by more than 605, and the 5 positions of Bing are deduced from this year's Heavenly Stems, and the 5 positions of Xu are deduced from this year's Earthly Branches. The birth year is the year of Bingxu.