Bazi (八字, “eight characters”), also called the Four Pillars of Destiny, is the Chinese art of reading a person’s life pattern from the calendar markers at the moment of their birth. It takes the year, month, day, and hour of birth, renders each as a pair of one tiangan (天干, “heavenly stem”) and one dizhi (地支, “earthly branch”), and reads the eight resulting characters as a single chart. The stem-branch cycle that supplies those pairs is the same one that labels years on a Chinese calendar; here it is reused for months, days, and hours too. What Bazi is, at its simplest, is three moves: lay out the four pillars, fix the Day Master, then read the ten gods.
What the four pillars are#
The four pillars (四柱, sizhu) are the stem-branch pair for each of four birth-time units:
| Pillar | Taken from | Stem | Branch |
|---|---|---|---|
| Year pillar | birth year | 甲 | 子 |
| Month pillar | birth month | 丙 | 寅 |
| Day pillar | birth day | 戊 | 辰 |
| Hour pillar | birth hour | 壬 | 戌 |
Four pillars × two characters each = eight characters, hence bazi (八字, “eight characters”). The example above reads 甲子 丙寅 戊辰 壬戌. Traditionally each pillar is also said to preside over a sphere of life: the year pillar over ancestry and early life, the month pillar over parents and young adulthood (and it is the pivotal yueling 月令, “monthly command,” for judging strength), the day pillar over oneself and spouse, the hour pillar over children and late life.
How the four pillars are set#
Each pillar is read from the birth moment, but each has its own rule for where one unit ends and the next begins — and this is where hand calculation goes wrong most often:
- Year pillar turns over at Lichun (立春, the Start-of-Spring solar term), not on lunar New Year and not on January 1. A birth just before Lichun still counts as the previous year — the single most common error.
- Month pillar turns over at the jie 节 terms of the solar cycle (Lichun, Jingzhe, and so on), not at the lunar-month boundary.
- Day pillar is looked up from a calendar (a wannianli 万年历); it cannot be done by mental arithmetic. Schools differ on whether the day changes at the 23:00 hour or at true midnight.
- Hour pillar runs in two-hour shichen 时辰 blocks (23:00–01:00 = zi shi 子时, and so on), and should be corrected by the longitude of the birthplace for true solar time.
Hand calculation therefore has to reconcile solar terms, the calendar, and time zones at once — easy to get wrong. The site’s Bazi Calculator builds those rules in: enter a birth time and it returns the four pillars and the ten gods directly, which is the practical way to lay out your own chart before reading the rest below.
The Day Master: the chart’s reference point#
Of the eight characters, one is special: the stem of the day pillar, called the Day Master (日主, rizhu, also riyuan 日元). It stands for the person themselves; the other seven characters are all read in relation to it. In the example 甲子 丙寅 戊辰 壬戌, the day pillar is 戊辰, so the Day Master is 戊 — yang earth. In Bazi terms this person is identified as “wu-earth” (戊土).
Fixing the Day Master is the first thing done after the four pillars are laid out, because everything that follows — judging whether it is strong or weak in the chart, and which elements help or hinder it — takes the Day Master as its reference point. The key idea for this introduction is that the Day Master is the chart’s coordinate origin, not “the best character.” How it is fixed and how its strength is judged is the subject of the Bazi Day Master article; here it is enough to know it is the pivot the rest of the chart turns on.
The ten gods: reading the relationships#
With a Day Master fixed, the other seven characters stop being isolated symbols and enter shengke (生克, generating-and-overcoming) relations with it. The naming system for those relations is the ten gods (十神, shishen). It is built by crossing two axes: the five wuxing (五行) relations (same / I generate / I overcome / overcomes me / generates me) with the yin-yang parity of the pair (same / opposite). Five times two gives ten:
| Relation to Day Master | Same parity | Opposite parity |
|---|---|---|
| Same as me | 比肩 bijian (shoulder) | 劫财 jiecai (rob wealth) |
| I generate | 食神 shishen (eating god) | 伤官 shangguan (hurting officer) |
| I overcome | 偏财 piancai (indirect wealth) | 正财 zhengcai (direct wealth) |
| Overcomes me | 七杀 qisha (seven killings) | 正官 zhengguan (direct officer) |
| Generates me | 偏印 pianyin (indirect resource) | 正印 zhengyin (direct resource) |
Taking the Day Master 戊 (yang earth) as the example: other earth is bijian / jiecai; earth generates metal, so metal is shishen / shangguan; earth overcomes water, so water is wealth; wood overcomes earth, so wood is officer / killing; fire generates earth, so fire is resource.
The crucial correction for a beginner: the ten gods are not good-or-bad labels. “Seven killings” (七杀) is not automatically bad, and “direct wealth” (正财) is not automatically good. Whether a given god helps or hurts depends on whether the Day Master is strong or weak in the whole chart — a strong Day Master benefits from being checked or drained, a weak one from being supported, so the same god can mean opposite things in different charts. This is the single intuition most worth retraining when starting Bazi.
A Western reader’s comparison: the natal chart#
The closest Western analogue to a Bazi chart is astrology’s natal chart (本命盘): both take the exact moment of birth as a starting point, both convert that moment into a system of symbols, and both read temperament and life tendencies from the relations among those symbols.
The difference is in what the symbols encode. A Western natal chart is spatial — it records where the planets actually sit along the ecliptic at the birth moment, a snapshot of the sky. A Bazi chart is cyclical — it encodes time, reading the stem-branch labels that the 60-term cycle assigns to that year, month, day, and hour, with no dependence on astronomical observation. So the ten gods read generating-and-overcoming relations among time-labels, not angular relations among bodies. Put plainly: a natal chart is a photograph of the sky; a Bazi chart is a set of serial numbers for time.
Classical source#
The practice of reading a person’s pattern from the stems and branches of their birth time is first attested in a Tang-dynasty epitaph by the essayist Han Yu (韩愈), Dianzhong Shiyushi Li Jun Muzhi Ming (《殿中侍御史李君墓志铭》, “Epitaph for Lord Li, Palace Censor”). The “Lord Li” of the title is Li Xuzhong (李虚中), a Tang official whom Han Yu credits with reading a person’s fortune from the stems and branches of the birth year, month, and day. Li worked from three pillars rather than four; the hour pillar and the day-stem-centered (Day Master) method were added later — attributed by tradition to Xu Ziping (徐子平) of the Five Dynasties period — and the received form was set down in the Song-dynasty compilation Yuanhai Ziping (《渊海子平》), the foundational text of the Ziping (子平) school from which all modern Bazi descends. The attribution to Xu Ziping is itself a later tradition’s retelling; the founding text that can be pointed to is Yuanhai Ziping.
Related: Bazi Calculator · Bazi Day Master · back to Destiny · Foundations