1. The year of Dingyou is a year in the lunar calendar, with sixty years as a cycle. For example, 1897, 1957, 2017... are all years of Dingyou. Sixty Dingyou is the oldest counting method. People born in the year of Dingyou are also called independent chickens.
2. The so-called chronology of the stems and branches of the lunar calendar means: in a literal sense, the stems and branches are equivalent to the trunks, branches and leaves of the tree. In ancient my country, the sky was the dominant one and the earth was the subordinate one. The connection between the sky and the branches is called the heavenly stems, the connection between the earth and the branches is called the earthly branches, and together they are called the heavenly stems and earthly branches, referred to as the stems and branches.
There are ten heavenly stems, namely A, B, C, D, Wu, Ji, Geng, Xin, Ren and Gui.
There are twelve earthly branches, namely Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai.
The ancients combined them in the order of Jiazi, Yichou, Bingyin... (that is, the heavenly stems rotate six times and the earthly branches rotate five times, which is exactly one cycle) without repetition. There are sixty pairs from Jiazi to Guihai, called one Jiazi.
The ancient Chinese used these sixty pairs of stems and branches to represent the serial numbers of the year, month, day, and time, and they continued to cycle. This is the chronology of the stems and branches.