Who is good at folk feng shui knowledge, come out and talk about it.

Heavenly stems and earthly branches is short for main branch. A, B, C, D, E, Ji, Geng, Xin, Ren and Gui are called ten heavenly stems, while Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai are called twelve earthly branches. Heavenly stems and earthly branches constituted the calendar year of the ancient Han nationality. According to the folklore of the Han nationality, the heavenly dryness corresponds to some omens. Ten branches and twelve branches are matched in turn, forming sixty basic units and forming a set of sub-disciplines. Judging from the Oracle Bone Inscriptions unearthed in Yin Ruins, the main branches were mainly used for recording dates, divination and cooperation among the Han people, and later they were more used in the fields of geomantic omen and technology. A calendar whose main branch is used to record the dates of a year is called a trunk branch calendar.