Starpath · Culture and history
Stems and branches
Ten stems and twelve branches pair up into a cycle of sixty.
The ten heavenly stems (甲乙丙丁戊己庚辛壬癸) and the twelve earthly branches (子丑寅卯辰巳午未申酉戌亥) are paired in order: 甲子, 乙丑, 丙寅 and so on to 癸亥. That makes sixty pairs; then the cycle starts again.
The cycle was already used to count days on Shang-dynasty oracle bones more than 3,000 years ago. Later it also named years, months and hours.
Each branch has an animal: rat, ox, tiger, rabbit, dragon, snake, horse, goat, monkey, rooster, dog and pig. The year of the horse is a year whose branch is 午.
Go deeper
Stems and branches alternate yang and yin: 甲 is yang, 乙 yin, and so on. Your birth year’s stem decides your four birth transformations, and its branch places several supporting stars.
A quick way to find a year’s stem: years ending in 4 are 甲, 5 乙, 6 丙, 7 丁, 8 戊, 9 己, 0 庚, 1 辛, 2 壬 and 3 癸, counting from the lunar new year.