What are the laws of the ancients in the zodiac?

The laws of the zodiac were determined by the ancients according to the heavenly stems and earthly branches in the time system. The heavenly stems are the ten characters of nails, B, C, D, E, Ji, G, Xin, Ren and Gui, and the earthly branches are the twelve characters of Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai. According to the combination of heavenly stems and earthly branches, the zodiac signs are formed, namely, mouse, ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, chicken, dog and pig. This combination law comes from ancient divination, so in ancient times, people predicted their own destiny according to the year of birth.