Yin-Yang, Heavenly Stems & Earthly Branches
The characters that fill the Four Pillars come from two interlocking sequences: the 10 Heavenly Stems and the 12 Earthly Branches.
Yin and Yang
Every element in Bazi carries a yin or yang polarity — not as opposites, but as complementary modes of the same energy. Yang is expansive, active, visible; yin is receptive, refined, internalized.
The 10 Heavenly Stems
| Stem | Element | Polarity | Common Quality |
|---|---|---|---|
| 甲 (Jiǎ) | Wood | Yang | Growth, pioneering |
| 乙 (Yǐ) | Wood | Yin | Flexibility, adaptability |
| 丙 (Bǐng) | Fire | Yang | Radiance, visibility |
| 丁 (Dīng) | Fire | Yin | Warmth, depth |
| 戊 (Wù) | Earth | Yang | Stability, containment |
| 己 (Jǐ) | Earth | Yin | Nourishment, detail |
| 庚 (Gēng) | Metal | Yang | Decisiveness, structure |
| 辛 (Xīn) | Metal | Yin | Refinement, precision |
| 壬 (Rén) | Water | Yang | Flow, ambition |
| 癸 (Guǐ) | Water | Yin | Wisdom, intuition |
The 12 Earthly Branches
The 12 Branches correspond to the 12-year animal cycle familiar in East Asian culture, but in Bazi they carry richer symbolic meaning:
| Branch | Animal | Season/Hour | Element |
|---|---|---|---|
| 子 Zǐ | Rat | 11pm–1am / Winter | Water |
| 丑 Chǒu | Ox | 1am–3am / Late Winter | Earth |
| 寅 Yín | Tiger | 3am–5am / Early Spring | Wood |
| 卯 Mǎo | Rabbit | 5am–7am / Spring | Wood |
| 辰 Chén | Dragon | 7am–9am / Late Spring | Earth |
| 巳 Sì | Snake | 9am–11am / Early Summer | Fire |
| 午 Wǔ | Horse | 11am–1pm / Summer | Fire |
| 未 Wèi | Goat | 1pm–3pm / Late Summer | Earth |
| 申 Shēn | Monkey | 3pm–5pm / Early Autumn | Metal |
| 酉 Yǒu | Rooster | 5pm–7pm / Autumn | Metal |
| 戌 Xū | Dog | 7pm–9pm / Late Autumn | Earth |
| 亥 Hài | Pig | 9pm–11pm / Early Winter | Water |
Why This Matters
Your Day Master — the Heavenly Stem of your Day Pillar — is the central reference point in Bazi analysis. Everything else in the chart is read in relation to it: how it's supported, challenged, expressed, and constrained by the surrounding characters.