What do you mean, doing things in the sky and underground?

As early as 2697 BC, when the Yellow Emperor, the ancestor of China, founded the country, heavenly stems and earthly branches made a great fuss about exploring the qi of heaven and earth and the five elements (water, fire and earth in Jin Mu), and started the ten-day work of A, B, C, D, E, Ji, G, Xin, Ren and Gui, and the work of Zi, Ugly, Yin, Mao, Chen, Si, Wu and Gui.

In the China calendar, the time for the moon to orbit the earth once (29.5306 days) is regarded as January, and the time for the earth to orbit the sun once (365.438+09 days) is regarded as a year. In order to make the average number of days in a year consistent with the number of days in the tropical year, a leap month is set up. According to records, in the 6th century BC, China began to coordinate the lunar calendar with the solar calendar by the method of 19.

Heavenly stems and earthly branches is a symbol designed for the convenience of 60 decimal places when people built calendars in the past. For ancient China people, the existence of heavenly stems and earthly branches was as simple as Arabic numerals. Later, these symbols were applied to maps, directions and time (time axis and space axis), so these numbers were endowed with more and more meanings.

The ancients (Yellow Emperor) observed Wang Shuo's moon and found that the two moons were about 59 days. 1February is generally more than 354 days (similar to the length of a tropical year), so the ancients got the concept of 12 months in a year. In the collocation diary method (ten-day dry), the yin-yang calendar was produced and developed in heavenly stems and earthly branches; It should be more mature in Xia, Shang and Zhou Dynasties.

Heavenly stems and earthly branches, referred to as Ganzhi for short, is used to arrange year numbers and dates in the summer calendar.

The calendar uses heavenly stems and earthly branches to arrange year numbers and dates, and the heavenly stems are crosses, so it is also called "ten stems". The order of arrangement is: A, B, C, D, E, Ji, G, Xin, Ren and Gui; * * * The order of the twelve characters is: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai. Among them, A, C, E, G and N are yang dryness, while B, D, J, Xin and Gui are yin dryness. Zi, Yin, Chen, Wu, Shen and Xu are the Yang branches, while Ugliness, Mao, Si, Wei, You and Hai are the Yin branches.

Dominate a stem with land, arrange them, with the heavenly stem in front, the earthly branch behind, the heavenly stem starting from the nail, the earthly branch starting from the child, the yang stem against the yang branch, and the yin stem against the yin branch (the yang stem against the yin branch and the yin stem against the yang branch), and get a cycle of 60 years. It is called "Sixty Jiazi" or "Flower Jiazi". In the past, China people used to mark the year, month, day and time with a cycle of 60 years.

Heavenly stems and earthly branches's twenty-two symbols are intricate and orderly, full of harmony and laws. It shows the law of natural operation, the interaction of real-time (time) space (orientation) and the result of interaction of Yin and Yang. China calendar contains the thought of Yin-Yang and Five Elements and the law of natural circulation.

Year: one year for each branch, after 60 branches, start from the beginning and repeat. Starting from Jiazi, it is called Jiazi or Huahua Jiazi 60 years later. It's called the chronology of cadres and branches.

Month: the first month begins in Yin, and the branches of the earth are fixed in each month, and then they are combined with the sky in turn; From the first month to the third month of the first year, February is Ding Maoyue and March is Chen Wu. From Jiaziyue to Guihaiyue, * * * sixty Jiazi, exactly five years.

Day: Starting from Jiazi Day, arranged in order, the 60th day happens to be a trunk-branch cycle.

Time: Starting from Jiazi, but the branch of punctuality is fixed, twelve hours a day.

Supplementary allusions:

According to legend, in the era of the Yellow Emperor, because of the harassment of the God Chiyou, the Yellow Emperor was worried about the people, so he fought Chiyou in the land of Zhuolu, and the bleeding could not be cured. So the Yellow Emperor fasted and bathed, and built altars to worship heaven and earth. The sky falls ten times (i.e. A, B, D, E, G, N, N). Twelve branches (that is, a letter that ugly Mao Yinchen applied for at noon). The emperor made ten pieces of dry circular cloth look like the sky and twelve pieces of square cloth look like the terrain. At first, doing it for the sky, supporting it for the ground, and then it can be cured. Later, the troublemakers divided the 10-day dry and 12-day branches into 60 Jiazi, and set the founding date of Huang Lai as Jiazi Year, Jiazi Month, Jiazi Day and Jiazi Time. This is the origin of heavenly stems and earthly branches.