What Is BaZi (Four Pillars of Destiny)?
BaZi (八字, "eight characters"), also called the Four Pillars of Destiny, is the Chinese method of describing a person through the year, month, day and hour of their birth, each written as a pair of characters: a heavenly stem and an earthly branch.
| Pillars | 4 (year, month, day, hour) |
|---|---|
| Characters | 8 (one stem + one branch per pillar) |
| Heavenly stems | 10: 甲 乙 丙 丁 戊 己 庚 辛 壬 癸 |
| Earthly branches | 12: 子 丑 寅 卯 辰 巳 午 未 申 酉 戌 亥 |
| Pillar combinations | 60 (the sexagenary cycle) |
| Year boundary | Lichun (Start of Spring, around Feb 4), not Jan 1 or Lunar New Year |
| Month boundary | The 12 "jie" solar terms |
| Day boundary | 23:00 local solar time (start of the Zi hour) |
| The "self" in the chart | The day stem, called the Day Master |
A worked example
A child born at noon on Lunar New Year's Day 2027 (February 6, 2027, Hong Kong) has the pillars 丁未 壬寅 丙辰 甲午. The day stem 丙 makes the Day Master Fire (The Sun). Counting visible stems and weighted hidden stems gives Wood 2, Fire 3.3, Earth 1.6, Metal 0, Water 1.1. The strength score is 69/100 (strong), so the simplified balance rule picks Water as the favorable element.
Notice the year pillar: 丁未. Lichun 2027 fell two days earlier, on February 4, 2027, so the Goat year had already begun in BaZi terms.
What a reading looks at
- Day Master and strength: is the self element supported by the season and the other characters?
- Ten gods: each other character is a role relative to the Day Master (resource, output, wealth, power, peer).
- Favorable elements: what would bring the chart toward balance.
- Luck pillars and years: ten-year cycles and each year's pillar meeting the natal chart.
How askjoss computes it
We convert your clock time to UTC with your birth city's time-zone history, then to true solar time using longitude and the equation of time. Solar terms come from an astronomical model, so the year and month boundaries are exact to the minute. Element strength is a 0–100 score; favorable elements follow simplified strength-balance (扶抑) rules. Full notes, including every simplification, are on How we calculate.
Common misconceptions
- "BaZi is the same as my zodiac sign." The sign is one branch out of eight characters.
- "The year starts on January 1 or at Lunar New Year." In BaZi it starts at Lichun.
- "Birth time does not matter." It sets the hour pillar and, near midnight or a solar term, can change the day or month.
- "A chart fixes your fate." Classical texts describe tendencies and timing; askjoss presents them as a lens for reflection.
Sources
- 《淵海子平》 (Song dynasty, attributed to Xu Dasheng): the foundational text of day-stem-centred BaZi.
- 《三命通會》 (Ming, Wan Minying): an encyclopaedic reference on pillars, relations and structures.
- 《子平真詮》 (Qing, Shen Xiaozhan): the classic on chart structure and useful gods.
- 《滴天髓》 (traditional, with Ren Tieqiao's Qing commentary): on balance and the flow of elements.
Related: Day Master · Five elements · Tong Shu almanac · Da Liu Ren · Qi Men Dun Jia · Zodiac clashes (Tai Sui)
Frequently asked questions
What does BaZi mean?
Ba means eight and zi means characters: the four pillars of birth, each with a stem and a branch, make eight characters.
Do I need my birth time for BaZi?
It helps. Without it you get three pillars (six characters) and lose the hour pillar; askjoss handles an unknown time and leaves out what depends on it.
Is BaZi the same as the Chinese zodiac?
No. Your zodiac animal is only the branch of your year pillar. BaZi reads all eight characters, with the day stem as the self.
How is BaZi calculated?
From the solar calendar: the year changes at Lichun, months at the jie solar terms, and the day pillar follows an unbroken 60-day cycle. The hour uses local solar time.
askjoss presents Chinese metaphysics as cultural tradition and a tool for self-reflection. It is not medical, legal, financial or psychological advice, and no reading can promise an outcome.