Where does China's heavenly stems and earthly branches timing come from?

As early as 2697 BC, when Huangdi, the ancestor of China, founded the country, he was ordered to explore the qi of heaven and earth and the five elements.

Some scholars have explored the unique phenomenon that the characters in the Ten-Day Dry were used as names from the names of all the emperors in China in the ancient Xia and Tang Dynasties. In his book "The Origin of Astronomy in China", Zheng believes that the myth of "Ten Days Born" originated from the ancient river in China, which is the embodiment of the concept of decimal chronology and should have originated from the fishing and hunting era of primitive society. The "Twelve Earthly Branches" evolved from the myth that "there are two births in October" before the Yin and Shang Dynasties, and then gradually evolved into twelve Chen. Therefore, Zheng concluded: "Twelve Poems is probably the creation of Xia people." Chen Zungui pointed out in the History of Astronomical Literature in China that "there may have been a branch in the Xia Dynasty more than 4,000 years ago". Du Shiran and others argued in the book History of Science and Technology in China that there was a ten-day dry calendar in Xia Dynasty, and the Shang Dynasty further used the dry calendar in Xia Dynasty, thus combining the ten-day dry calendar with the twelve earthly branches to form a sixty-week calendar.

Around the end of the Warring States Period, the historical book Shi Ben, compiled according to the materials accumulated by historians of various countries for a long time, said: "Rongcheng is the calendar and Daladi is the Jiazi", and Shangshu just explained: "Both of them are ministers of the Yellow Emperor. Since the Yellow Emperor, Jiazi has been used to mark the day, and Jiazi is once every 60 days. It seems that the main branch was created by Darrouy. He "takes five elements of love, takes advantage of the bucket machine, enlightens Party A and Party B, and calls it dry; The ugly son is named after the moon, which is called Zhi. There is something in the sky, it is used during the day, there is something underground, and the moon is used. The difference between yin and yang makes it a branch name. "

The Five Elements of the Sui Dynasty agreed that cadres and party branches were created through great efforts.

The original origin of heavenly stems and earthly branches is still inconclusive. If we look at cultural relics, there are a large number of records of dry branches and branches used to record the days among the Oracle bones unearthed in Yin Ruins in the past hundred years (after Pan Geng moved the capital to Yin, Shang Dynasty was also called Yin), and the word with the highest frequency in Oracle Bone Inscriptions is also dry branches.

From the discovery of Oracle Bone Inscriptions in Shang Dynasty, more than 99% of the contents are related to divination, which is what we often call "Oracle Bone Inscriptions", but Oracle Bone Inscriptions is not the whole content of Oracle Bone Inscriptions. In addition, there are a few but very important other kinds of inscriptions that have nothing to do with divination. For example, the inscription "List of Branches and Branches" in it. The inscription of "the surface of the liver" is a special inscription in Oracle Bone Inscriptions, belonging to the epigraph inscription. This inscription is a list of 60 branches named ten heavenly stems: A, B, C, D, E, Ji, G, Xin, Ren, Gui and twelve branches: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai. There are 60 "branch tables" engraved on this Jiazi table, which was the spectrum table used by people to check the branch period at that time. The branch table can be said to be the earliest calendar in China.