What does Jiayin mean?

One day, this day is called Jiayin, just as we say this day is 1.

Unlike now, the ancient calendar years are arranged in a certain regular order of 10 and 12 days. On the day of "Jiayin", heavenly stems and earthly branches is arranged together, so it is called Jiayin Day, the next day is the second day, and the next day is the third day.

Noun explanation:

Jiayin is one of the main branches, and the order is 5 1. The former is Guichou and the latter is Yi Mao. On the five elements of Yin and Yang, the first part of the heavenly stems belongs to Yang wood, and the second part of the earthly branches belongs to Yang wood, which is a good proportion. Jiayin is also the name of a political journal in the early years of the Republic of China and the first revolutionary civil war.