Where did the sixties come from?

Constantly understand the structure of the Book of Changes, and recently found that 60 Jiazi is extraordinary! I vaguely feel that from the point of view I have seen in the past, it is not an understanding of sixty jiazi! Sixty jiazi is like putting on a mysterious coat? I haven't seen her for thousands of years.

Sixty jiazi consists of ten stems and twelve branches.

Heavenly stems are written in the following order: a, b, c, d, e, g, n, n, 10.

The addresses are written in the following order: Ugly son Yin Mao Tatsumi applied for 12 at noon.

A of Tiangan sorting head and sub of address sorting head began to combine, forming Jiazi, Yechou, Bingyin, Ding Mao, Chen Wu, Keith, Wu Geng, Xinwei, Renshen, Gui You, JOE, Yihai, Bingzi and other groups ...