Brief Introduction to the ten Heavenly Stems
The ten Celestial or Heavenly Stems (Chinese: 天干; pinyin: tiāngān) are the elements of an ancient Chinese cyclic character numeral system: Jia (甲), Yi (乙), Bing (丙), Ding (丁), Wu (戊), Ji (己), Geng (庚), Xin (辛), Ren (壬), Gui (癸). They were used for dates as early as the Shang Dynasty, and are now used with the twelve Earthly Branches in the Sexagenary cycle. They are associated with the concepts of yin and yang and the Five Elements.They are associated with the concepts of yin and yang and the Five Elements.