What Are the Four Pillars?
The Four Pillars are the Year Pillar, Month Pillar, Day Pillar, and Hour Pillar. Each pillar consists of one Heavenly Stem and one Earthly Branch. Together, the four pillars contain eight characters, hence the term "Bazi" (Eight Characters). The Four Pillars encode the temporal coordinates of a person's birth; the destiny analyst interprets life patterns by examining the Five Elements composition and Stem-Branch relationships across the pillars.
The Meaning of Each Pillar
| Pillar | Components | Symbolic Domain |
|---|---|---|
| Year Pillar | Year Stem, Year Branch | Ancestors, childhood, social background |
| Month Pillar | Month Stem, Month Branch | Parents, youth, career |
| Day Pillar | Day Stem, Day Branch | Self (Day Master), spouse |
| Hour Pillar | Hour Stem, Hour Branch | Children, later years, inner depths |
The Special Status of the Month Pillar
Among the Four Pillars, the Month Pillar is the most critical. The Month Branch — known as the "Month Command" (Yueling) — determines the prevailing Solar Term and the waxing and waning of the Five Elements at the time of birth. It is the primary basis for judging whether the Day Master has Seasonal Support (Deling) and serves as the foundation for determining Chart Structure (Geju). Traditional theory regards the Month Command as the "outline" (tigang), meaning it exerts a commanding influence over the entire chart.
Arrangement Rules of the Four Pillars
The Four Pillars follow the sexagenary cycle of Heavenly Stems and Earthly Branches (the Sixty Jiazi). Month divisions are based on Solar Terms (not lunar calendar months), and the boundary between one day and the next is determined by the midnight Zi-hour. When calculating the Luck Cycle, the Month Pillar serves as the reference point, with the sequence proceeding forward or backward according to gender and the Yin-Yang polarity of the birth year stem.