Heavenly Stems & Earthly Branches

The 10 Stems and 12 Branches that form the language of Bazi

The 10 Heavenly Stems (天干)

The Heavenly Stems are the visible, active energy in a chart. There are 10, each with a yin/yang polarity and an element association: Yang Stems: 甲 (Jia) — Yang Wood, 丙 (Bing) — Yang Fire, 戊 (Wu) — Yang Earth, 庚 (Geng) — Yang Metal, 壬 (Ren) — Yang Water. Yin Stems: 乙 (Yi) — Yin Wood, 丁 (Ding) — Yin Fire, 己 (Ji) — Yin Earth, 辛 (Xin) — Yin Metal, 癸 (Gui) — Yin Water. The Heavenly Stem of your Day Pillar is your Day Master — the most important single character in your entire chart.

The 12 Earthly Branches (地支)

The Earthly Branches represent the hidden, underlying energy. Each branch corresponds to a zodiac animal, a two-hour time period, a season, and contains hidden Heavenly Stems: 子 (Zi): Rat, 23:00-01:00, Winter. 丑 (Chou): Ox, 01:00-03:00. 寅 (Yin): Tiger, 03:00-05:00, Spring. 卯 (Mao): Rabbit, 05:00-07:00. 辰 (Chen): Dragon, 07:00-09:00. 巳 (Si): Snake, 09:00-11:00, Summer. 午 (Wu): Horse, 11:00-13:00. 未 (Wei): Goat, 13:00-15:00. 申 (Shen): Monkey, 15:00-17:00, Autumn. 酉 (You): Rooster, 17:00-19:00. 戌 (Xu): Dog, 19:00-21:00. 亥 (Hai): Pig, 21:00-23:00, Winter.

The Sexagenary (60 Jiazi) Cycle

A Heavenly Stem and an Earthly Branch combine to form a "pillar." Since 10 and 12 have a least common multiple of 60, there are exactly 60 possible combinations — called the Sexagenary Cycle or "60 Jiazi." Each year, month, day, and two-hour period has its own stem-branch pair. This cycle has been used continuously in China for over 3,000 years to track time.

Hidden Stems (藏干)

Each Earthly Branch contains 1-3 "hidden" Heavenly Stems. For example, the Branch 寅 (Yin Tiger) contains 甲 (Jia Wood), 丙 (Bing Fire), and 戊 (Wu Earth). These hidden stems add remarkable depth to chart analysis — they represent potential, subconscious tendencies, and latent talents that may not be immediately visible from the surface stems alone.