The 60-year cycle that keeps time in Chinese cosmology.
Ten Heavenly Stems (天干) pair with twelve Earthly Branches (地支) to produce sixty unique combinations — the jiazi (甲子) cycle. One cycle covers sixty years, sixty days, or sixty two-hour watches, depending on context. Each branch is also mapped to one of the twelve zodiac animals. Together, the stems and branches are the oldest continuously-used calendar system on Earth.
Beyond pairing with stems, branches interact with each other through punishments, conflicts, and affinities. These relationships shape the reading of a chart in Wen Wang Gua and BaZi.
子—卯
Bullying Punishment
Zi (Rat) and Mao (Rabbit) punish each other
辰
Self-Punishment
Chen (Dragon) punishes itself
亥
Self-Punishment
Hai (Pig) punishes itself
午
Self-Punishment
Wu (Horse) punishes itself
酉
Self-Punishment
You (Rooster) punishes itself
寅—巳
Unkind Punishment
Yin (Tiger) punishes Si (Snake), Si punishes Shen (Monkey), Shen punishes Yin