BaZi Chart Construction (八字排盤)
Manual charting requires converting a birth date and time to the Four Pillars (四柱) using the traditional Chinese solar calendar (農曆 / 節氣). Each pillar consists of a Heavenly Stem (天干) and Earthly Branch (地支).
The Four Pillars
- Year Pillar (年柱): Determined by the solar year, changing at the Chinese New Year (立春 Li Chun). Represents ancestral background and early childhood environment (ages 0–15).
- Month Pillar (月柱): The most critical pillar. Determined by the 24 Solar Terms (二十四節氣). The Month Branch is the "Month Command" (月令) — the foundation of chart structure.
- Day Pillar (日柱): The Day Stem is the Day Master — the core Self. Day calculation requires a conversion table or algorithm based on the 60 Jia Zi cycle.
- Hour Pillar (時柱): Determined by the 12 Chinese double-hours. The Hour Branch reveals hidden characteristics and the relationship with children and late-life destiny.
Hidden Stems (藏干)
Each Earthly Branch contains one to three Hidden Stems (藏干) that represent the full elemental content of that position. These are essential for calculating the Ten Gods and assessing elemental strength:
- Zi (子) — Rat: Gui Water (癸水)
- Chou (丑) — Ox: Ji Earth (己土), Xin Metal (辛金), Gui Water (癸水)
- Yin (寅) — Tiger: Jia Wood (甲木), Bing Fire (丙火), Wu Earth (戊土)
- Mao (卯) — Rabbit: Yi Wood (乙木)
Luck Pillars (大運 Da Yun)
Luck Pillars represent 10-year periods that overlay the natal chart with a changing elemental influence. They are calculated from the distance between the birth date and the next (for males, Yang year) or previous (for females, Yang year) major solar term:
- Identify the birth gender and year polarity (Yang or Yin year)
- Count the days to the appropriate solar term boundary
- Divide by 3 to get the starting age (each 3 days = 1 year of life)
- Each Luck Pillar spans 10 years, derived from the Month Pillar's sequential neighbors in the 60 Jia Zi cycle