1, god damn it:
Any year after A.D.: A.D. -3= the number of digits at the end of the year, negative number plus 10.
Any year BC: year-end digits +8= year-end.
(Because AD 3 is the year of Guihai, the heavenly stems are the cycle of 10. In AD 4, the heavenly stems were a, 4-3= 1. Because there is no year 0, the heavenly stems in BC are the last digit-3+1,and then+10 becomes a positive number)
2, calculate the ground branch:
Any year after A.D.: (A.D. year -3)÷ 12, the remainder 0- 1 1 is the annual branch, and the negative number is added with 12, and 0 is regarded as 12.
Any year in BC: (AD year -2 years) ÷ 12, and the remainder-1-0 is the annual branch. Add 12 to make it a positive number, and 0 is regarded as 12.
Another one:
1, two digits at the end of AD +9 = annual expenditure (applicable to1800-1899);
2.AD+1 last two digits = annual expenditure (applicable to1900-1999);
3. Two digits at the end of the year +5= annual expenditure (applicable to 2000-1999);
Beginning of spring is the boundary of the main branch in 2008, not the Spring Festival. For example, whether February 4th 1964 of the lunar calendar is1February 2nd1day or the first year of the lunar calendar; However, although February 5th of the lunar calendar, 1964 Gregorian calendar is1February 22nd, this day is already in beginning of spring, which is an appropriate year for Chen Jianian.
Extended data:
Ganzhi calendar is the product of ancient civilization, also known as solar calendar or China solar calendar, which is an abstruse calendar. This is a calendar marked with 60 different groups of heavenly stems and earthly branches. It mainly consists of four parts: dry branch year, dry branch month, dry branch day and dry branch time. It takes beginning of spring as the beginning of the year and festivals as the beginning of the month. When you get old, you will return to that year, and one section is a month. Ganzhili discussed the relationship between the sun and the earth through heavenly stems and earthly branches, and the 24 solar terms and the zodiac were the basic contents.
It manages years and months and has 24 solar terms. The 24 solar terms are divided according to the ecliptic plane. Twelve months divided by twenty-four solar terms, each month contains two solar terms, and there is no leap month. Twenty-four solar terms are related to the periodic motion of the earth around the sun, and their days and months are determined by the apparent motion of the sun, and have nothing to do with the moon phase.
Also different from the usual solar calendar (such as the Gregorian calendar), the length of the Gregorian calendar is artificially specified and has nothing to do with the astronomical phenomena; The year, month and day of the elephant trunk calendar are determined by the astronomical phenomena and do not need to be adjusted artificially. It is a calendar that completely conforms to the laws of the astronomical phenomena. At present, dry calendars are still popular in books such as perpetual calendars, which are used for astrology, geomantic omen and numerology.
Baidu Encyclopedia-heavenly stems and earthly branches