Gan 干 (Heavenly Stems) and Zhi 支 (Earthly Branches)
Also related to the 28 lunar houses, the ten Heavenly Stems which reflect the energy of Heaven (Heavenly Stems Table, below) and the twelve Earthly Branches, which represent the energy of Earth (Earthly Branch Table, also below).
How long have the GanZhi been in use in China?
Evidence suggests that the Stems and Branches have existed even before the invention of the Chinese characters. The symbols for the Stems and Branches are seen in the unearthed ancient Chinese oracle bones from the Shang Dynasty (1766 to 1111 BCE).
GanZhi and Five Elements
As noted in the tables (download the PDF links below), a given Stem or Branch also contains the energy of one of the Five Elements. As a brief example, the first Heavenly Stem, Jia, contains the energy of Yang Wood. The first Earthly Branch, Zi, contains the energy of Yang Water.
GanZhi and YinYang
Traditional Chinese astrology names each year according to its Heavenly Stem and Earthly Branch. For instance, the year 2014 was called JiaWu 甲午. Jia is the Heavenly Stem and it means Yang Wood. Wu is the Earthly Branch and it means Yang Fire. The astrological animal associated with Wu is the horse. This is the origin of the animals you see on menus in Chinese restaurants – they the Earthly Branch energy made manifest in a living symbol we can all relate to.
GanZhi and Chinese Astrology
Naming years in this fashion functions not only to keep track of the year but also to characterize the energy of that time period. The energies of each month, date, or even time of day (in two-hour increments) are also reflected by a Heavenly Stem and Earthly Branch. An individual’s astrologcial chart is calculated through the Stems and Branches.
If you would like to learn more about the GanZhi, the heart of all Chinese wisdom traditions, please read Heavenly Stems and Earthly Branches, by Master Wu and Dr. Karin Taylor Wu.