干支

noun

the Heavenly Stems and Earthly Branches; the traditional Chinese sexagenary cycle

The ten Heavenly Stems (甲, 乙, 丙, 丁, 戊, 己, 庚, 辛, 壬, 癸) combine with the twelve Earthly Branches (子, 丑, 寅, 卯, 辰, 巳, 午, 未, 申, 酉, 戌, 亥) to form sixty unique combinations. Yang stems pair with yang branches and yin with yin. Originally used for recording days, now primarily used for years in the traditional lunar calendar.