What Is Bazi? Four Pillars

BAZI 八字 · FOUR PILLARS · TEN GODS · LI CHUN DATES

Last updated: October 3, 2026

KEY TAKEAWAYS / TL;DR

◈Bazi, also called the Four Pillars of Destiny or Eight Characters, is a Chinese birth-chart system built from the Stem-Branch pairs of the birth year, month, day, and hour.
◈A chart uses 10 Heavenly Stems, 12 Earthly Branches, hidden stems, Five Element relationships, and the Day Master to describe symbolic temperament and timing patterns.
◈Bazi dates are not simply lunar-calendar dates: many charts use Li Chun for the Year Pillar and solar terms for Month Pillars, so early-February births need a stated calendar rule.

By the Numbers

4: Pillars; Year, month, day, and hour define the chart.
8: Characters; Each pillar has one Stem and one Branch.
60: Jiazi Cycle; Every pillar is drawn from the sexagenary cycle.

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Bazi draws on Han-period correlative cosmology (206 BCE to 220 CE), where calendars, seasons, and social life were read as linked patterns. Its stem-branch timekeeping is older: stem-branch day records appear on Shang oracle bones from around 1600 to 1046 BCE.

Tang scholar Li Xuzhong (761 to 813 CE) is associated with earlier three-pillar methods based on year, month, and day. The later four-pillar method adds the hour and places the Day Master (日主), the Heavenly Stem of the birth day, at the center. That approach is linked with the Song-era Xu Ziping tradition and texts such as Yuanhai Ziping (渊海子平).

CLASSICAL SOURCE NOTES

Yuanhai Ziping: Used here for the Day Master-centered reading frame and the Da Yun starting-age method. It anchors the reading in classical method.; Primary tradition: 《渊海子平》, especially sections on Day Master and Da Yun.
San Ming Tong Hui / Di Tian Sui: Used for hidden-stem taxonomy, seasonal balance, stem imagery, and the vocabulary behind a chart.; Reference tradition: 《三命通会》 and 《滴天髓》 commentarial line.

Bazi Life Trajectory chart example showing luck pillar cycles, annual flow, and life phase intensity over time — Example Life Trajectory chart showing how Bazi luck pillars and yearly timing can be visualized as changing life-phase intensity.

THE ANATOMY OF A BAZI CHART

FOUR PILLARS · STEM & BRANCH MAPPING

YEAR

甲

Jiǎ

Wood

子

Zǐ

Water

MONTH

丙

Bǐng

Fire

寅

Yín

Wood

DAY (MASTER)

庚

Gēng

Metal

申

Shēn

Metal

HOUR

戊

Wù

Earth

辰

Chén

Earth

HEAVENLY STEMS

The ten Heavenly Stems: visible Five Element and Yin-Yang markers in the chart

甲JiǎYang Wood: Towering tree. Upright, noble, stubborn. Natural leaders who stand firm.
乙YǐYin Wood: Vines and flowers. Flexible, diplomatic, graceful. Adapts to surroundings.
丙BǐngYang Fire: Blazing sun. Bold, generous, warm. Commands attention effortlessly.
丁DīngYin Fire: Candle flame. Gentle warmth, focused, intimate. Illuminates quietly.
戊WùYang Earth: Mountain. Stable, immovable, reliable. The rock others depend on.
己JǐYin Earth: Fertile soil. Nurturing, receptive, productive. Creates conditions for growth.
庚GēngYang Metal: Battle axe. Decisive, direct, justice-oriented. Cuts through ambiguity.
辛XīnYin Metal: Polished gem. Refined, sensitive, detail-oriented. Beauty through precision.
壬RénYang Water: Ocean and rivers. Unstoppable momentum, wisdom. Goes around all obstacles.
癸GuǐYin Water: Morning dew. Quiet nourishment, intuition, spirituality. Works behind the scenes.

EARTHLY BRANCHES

The twelve Earthly Branches: time, season, zodiac, and hidden-stem containers

子RatWater: 23:00–01:00
丑OxEarth: 01:00–03:00
寅TigerWood: 03:00–05:00
卯RabbitWood: 05:00–07:00
辰DragonEarth: 07:00–09:00
巳SnakeFire: 09:00–11:00
午HorseFire: 11:00–13:00
未GoatEarth: 13:00–15:00
申MonkeyMetal: 15:00–17:00
酉RoosterMetal: 17:00–19:00
戌DogEarth: 19:00–21:00
亥PigWater: 21:00–23:00

HIDDEN STEMS (CANG GAN)

Each Earthly Branch conceals one to three Heavenly Stems within, referred to as Hidden Stems. The Primary Qi defines the branch's dominant element. The Secondary and Residual Qi, when present, represent subordinate energies. Understanding hidden stems is essential for analyzing the full elemental composition of a Bazi chart.

BRANCH	PRIMARY QI	SECONDARY QI	RESIDUAL QI
子Rat	癸Water	—	—
丑Ox	己Earth	癸Water	辛Metal
寅Tiger	甲Wood	丙Fire	戊Earth
卯Rabbit	乙Wood	—	—
辰Dragon	戊Earth	乙Wood	癸Water
巳Snake	丙Fire	庚Metal	戊Earth
午Horse	丁Fire	己Earth	—
未Goat	己Earth	丁Fire	乙Wood
申Monkey	庚Metal	壬Water	戊Earth
酉Rooster	辛Metal	—	—
戌Dog	戊Earth	辛Metal	丁Fire
亥Pig	壬Water	甲Wood	—

Source: Wikipedia — Earthly Branches, §Hidden stems; San Ming Tong Hui

LUCK PILLARS & ANNUAL FORTUNE

Beyond the birth chart, Bazi uses two timing layers to compare longer periods with yearly themes.

Major Luck Cycle (Da Yun)

The Luck Pillars divide life into ten-year phases, each governed by a unique stem-branch pair derived from the Month Pillar. The direction of progression depends on the gender and the Yin/Yang polarity of the birth year: Yang year males and Yin year females count forward through the sexagenary cycle; the reverse counts backward.

The onset age of the first Luck Pillar is calculated by counting the number of days from the birth date to the next (or previous) seasonal node, then dividing by three. Each day equaling four months of life. This methodology is documented in the Yuanhai Ziping.

Annual Fortune (Liu Nian)

Each calendar year carries its own stem-branch pair from the sexagenary cycle. When this Annual Pillar interacts with the natal chart and the current Luck Pillar, readers compare harmonies, clashes, and combinations to identify the year's main symbolic themes.

MONTH DETERMINATION: SOLAR TERMS

A critical distinction in Bazi: the month pillar is determined by Solar Terms, not by the first day of the lunar month. Each month begins at a specific seasonal node. For example, the first month (Yin / Tiger) starts at Li Chun (Start of Spring), typically February 3 to 5. This means two people born in the same lunar month may have different month pillars if a solar term falls between their birthdays.

Source: Wikipedia — Four Pillars of Destiny, §Structure; Chinese calendar §Solar terms

Worked example: year and month pillars across Li Chun

These two synthetic birth times use this calculator’s local-clock mode, with birthplace left blank and no true solar time correction. They fall before and after Li Chun in 2026; neither is a user profile or the exact solar-term transition.

Year and month pillar comparison across Li Chun
Entered date and time	Year pillar	Month pillar
2026-02-03 12:00	乙巳 · Yi Si	己丑 · Ji Chou
2026-02-05 12:00	丙午 · Bing Wu	庚寅 · Geng Yin

Both dates are in February, but their year and month pillars differ. Near a solar-term boundary, check the full recorded time and birthplace rather than the calendar month alone. These dates are not a universal annual cutoff.

Check year and month pillars in the free calculator Read our calendar and time conventions

Why can two Bazi calculators show different pillars?

Before comparing a chart, compare the calculation settings. A different result is not automatically an error: the year boundary, solar-term rule, time basis, and birthplace correction must be stated together.

Year boundary: Li Chun versus Chinese New Year can assign an early-February birth to different Year Pillars.
Month boundary: Bazi month pillars commonly follow Solar Terms rather than the first day of a lunar month.
Time basis: Local clock time and local civil time with birthplace-based historical time-zone and true-solar-time correction are different inputs.
Input record: Keep the full birth date, time, birthplace, and stated calculation mode so another person can reproduce the comparison.

CLASSICAL TEXTS

The foundational canon of Four Pillars methodology, accumulated over a millennium of practice:

Yuanhai Ziping《渊海子平》Song / Ming Dynasty: The foundational canon of the Four Pillars method, attributed to Xu Ziping. Establishes the Day Master framework and systematizes stem-branch interactions.
San Ming Tong Hui《三命通会》Ming Dynasty (Wan Minying): A comprehensive Bazi encyclopedia, cataloguing all 60 Jiazi day pillars with detailed traditional personality and life-theme notes for each.
Di Tian Sui《滴天髓》Song Dynasty (attributed): A compact philosophical treatise on Bazi. Known for its cryptic verses, heavily annotated by Qing-era scholars like Ren Tieqiao.
Qiongtong Baojian《穷通宝鉴》Ming / Qing Dynasty: A major reference on seasonal adjustment (Tiao Hou Yong Shen) — selecting the Useful God based on the month of birth and seasonal balance.

Source: Wikipedia — Four Pillars of Destiny §History & §Structure; Earthly Branches §Hidden stems; San Ming Tong Hui; Yuanhai Ziping §Da Yun; Di Tian Sui

FREQUENTLY ASKED QUESTIONS

What is Bazi in plain terms?+

Bazi is a traditional Chinese birth-chart system that converts the birth year, month, day, and hour into four Stem-Branch pairs. Readers use those pairs to compare the Day Master, Five Elements, Ten Gods, and timing cycles as symbolic reference layers.

Why are there multiple elements inside an Earthly Branch?+

Earthly Branches can contain one to three Hidden Stems. This means a branch may carry more than one Five Element reference, so readers usually check the hidden stems before judging chart balance or Day Master strength.

What are Hidden Stems and why do they matter?+

Hidden Stems are the one to three Heavenly Stems concealed within each Earthly Branch. For example, the Tiger (Yin) branch contains Jia Wood (primary), Bing Fire (secondary), and Wu Earth (residual). They help readers evaluate elemental strength with more nuance than surface-level branch attributes alone.

What is the difference between Da Yun and Liu Nian?+

Da Yun (Luck Pillars) are ten-year cycles derived from the Month Pillar. Liu Nian (Annual Fortune) is the yearly stem-branch that interacts with both the natal chart and the current Luck Pillar. Da Yun gives the broader period context; Liu Nian helps interpret yearly themes.

Why does Bazi use solar terms instead of lunar months?+

Bazi divides months by Solar Terms (Jie Qi), not by the lunar calendar's first day. For example, the first month (Yin / Tiger) begins at Li Chun (Start of Spring), typically February 3-5. This is because Bazi tracks the Earth-Sun positional relationship (ecliptic longitude), not the Moon's cycle.

Does the Bazi Year Pillar start at Li Chun or Chinese New Year?+

Many Four Pillars systems switch the Year Pillar at Li Chun, Start of Spring, while public zodiac and festival calendars usually follow Chinese New Year. People born between those boundaries may have a public zodiac label that differs from the Bazi Year Pillar, so the charting rule should be stated clearly.

How does Life Trajectory relate to traditional luck pillars?+

Life Trajectory organizes Da Yun, annual fortune, and chart interactions into a timeline. It helps compare phase intensity and timing rhythm as a visual layer for the traditional Bazi timing system.

What kind of method is Bazi?+

Bazi uses a traditional calendar, Five Element categories, and symbolic observation to organize a chart, helping readers explore the relationships among the Day Master, chart structure, and timing cycles.