Heavenly Stems and Earthly Branches
2 min readHeavenly Stems and Earthly Branches
Heavenly Stems and Earthly Branches are known as Stem-Branch of Ganzhi. The 10Heavenly Stems，the elements of an ancient Chinese cyclic character numeral system，are Jia，Yi，Bing，Ding，Wu，Ji，Geng，Xin，Ren and Gui. The 12 Earthly Branches are Zi，Chou，Yin，Mao，Chen，Si，Wu，Wei，Shen，You，Xu and Hai. Each Heavenly Stem is paired with an Earthly Branch to form the Ganzhi，the sexagenary cycle that starts with Jia Zi.
Earthly Branches can be used to count time of years，months and hours.When counting years，people use them with the 12 Chinese zodiacs and strictly one Earthly Branch corresponds to one fixed zodiac.For example，our ancestors divided a day and night into 1 sections and named each as a Shi Chen，which is equal to today’s two hours and has a fixed Earthly Branch name.Time from 23：00 to 1：00 is decided to be the first one，Zi Shi，then the second two hours Chou Shi，etc.
As the Heavenly Stems take the decimal system to account，and the Earthly Branches a duodenary system with the advantage of noting the 12 months，the combination of these two sets became a sexagesimal one.This is mapped to the year，month and day and repeatedinfinitely.Thus here came a way of counting time which has been passed down through thousands of years.A year can be represented by the composition of two characters，one from the heavenly set，and one from the other.For example，the year 1924，1984 and 2044are all Jia Zi Years.The following years of 1925，1985 and 2045 are all Yi Chou Years which is the next combination in the sequence.Similarly，if this month is Yi Chou，then the next month is Bing Yin which is the next combination in the sequence.The same applies to the day.If today is Jia Zi，then tomorrow is Yi Chou.The cycle is repeated every 60 days.And if this Shi Chen is Ding You，then the next Shi Chen is Wu Xu，the next combination in the cycle.
