Bazi basics: reading the eight characters

The four pillars

Bazi, 八字, means “eight characters”: the four stem-and-branch pairs assigned to a person's birth year, month, day and hour. Together they form the four pillars, or sizhu (四柱), of a traditional Chinese birth-divination chart. Practitioners interpret their relationships as indications of temperament, family ties, work and changing fortune. These meanings belong to divination; the calendar calculation itself establishes only the birth-time labels.

Each pillar contains a heavenly stem followed by an earthly branch. The day's heavenly stem, called the day master, represents the person whose chart is being read. The other characters supply the relationships and circumstances through which practitioners interpret that central reference point.

Chart columns may run from right to left or from left to right, so their labels matter. A person's birth-year animal identifies only the year branch: it leaves the other seven characters unspecified.

A worked example

For February 10, 2024, at 12:00, UTC+8, the following chart uses ordinary zone-clock time without a local-solar-time correction. Its year begins at the exact Lichun instant and its months at the relevant solar-term instants.

The date falls after Lichun, Beginning of Spring, on February 4, so the year pillar is Jia-Chen. It lies in the Yin month, whose stem is Bing in a Jia year. The day is independently Jia-Chen in the continuous sixty-day count. Noon falls in the Wu interval, from 11:00 to just before 13:00, which takes the stem Geng on a Jia day.

The repeated Jia-Chen labels come from separate year and day cycles. For interpretation, Jia in the day column is the day master; Jia in the year column is another stem to compare with it.

Reading the day master and its relationships

The day master, or rizhu (日主), gives the chart its point of view. Each heavenly stem belongs to one of the five phases—Wood, Fire, Earth, Metal and Water—and has a yin or yang classification. Jia is yang Wood; Yi is yin Wood. In the worked example, relationships are therefore read from the standpoint of Jia, yang Wood.

Within the five-phase scheme, Water generates Wood, Wood generates Fire, Wood controls Earth, and Metal controls Wood. Another Wood stem shares the day master's phase. These five relationships provide the basis for the chart's interpretive vocabulary.

The Ten Gods

The Ten Gods, or shishen (十神), are names for relationships to the day master. Each of the five phase relationships divides in two according to whether the other stem has the same yin–yang polarity as the day master or the opposite polarity. The names describe symbolic roles, not ten deities added to the birth chart.

Some charts call Companion “Friend” and Seven Killings “Indirect Officer.” A chart need not contain all ten categories.

In the worked example, the year stem Jia shares both phase and polarity with the day master, making it Companion. Bing is yang Fire, which Jia Wood generates, so it is Eating God. Geng is yang Metal, which controls Jia Wood, so it is Seven Killings. The dramatic name identifies a controlling relationship; it does not by itself predict violence or disaster.

Practitioners also read relationships between those other stems. Fire controls Metal, so they may examine Bing as a restraint on Geng. This connects the chart's themes of expression and pressure. Whether that interaction is judged helpful depends on the support each stem receives elsewhere in the chart.

Hidden stems and the branches

An earthly branch carries more information than its animal name or main phase. Its hidden stems are the heavenly stems assigned to it by traditional correspondence. They are often printed beneath the branch and read in relation to the day master, just like the stems at the top of the chart.

Chen, which appears twice in the example, contains Wu Earth, Yi Wood and Gui Water. Relative to Jia, these are Indirect Wealth, Rob Wealth and Direct Resource. The chart has no Water among its four visible heavenly stems, yet Water appears through Gui within Chen. This is one reason that counting only the top row gives an incomplete picture.

Hidden stems do not add characters to the four pillars. They explain the branches' internal correspondences. Nayin is a different classification again: it assigns a name and phase to a complete stem–branch pair. A Nayin phase can differ from the phase of that pair's heavenly stem without either label being mistaken.

Season, strength and the whole pattern

The month branch establishes the chart's seasonal setting, often called the month command. In traditional five-phase interpretation, Wood is seasonally vigorous in spring. The example's Yin month therefore gives Jia a different setting from an autumn birth. Yin also contains Jia as a hidden stem, giving the day master a root: a presence within a branch that practitioners treat as support.

A reading weighs seasonal conditions, roots, supporting stems and the forces that restrain or draw on the day master. “Strong” and “weak” describe its relative support within this scheme, rather than physical strength or a person's worth. A stem can have seasonal support yet face substantial restraint from the rest of the chart; an out-of-season stem can still receive strong support from its roots and companions.

The next question is which relationships help the overall pattern. In a strength-based reading, an already well-supported day master may benefit from an outlet or restraint, while a poorly supported one may be judged to need support. A favourable phase is consequently not just whichever phase appears least often. Equal quantities of all five phases are not the aim, and a missing phase is not automatically something to add.

Pillar position supplies another layer of meaning. A common traditional arrangement associates the year with ancestry and early circumstances, the month with parents and upbringing, the day branch with a spouse or partnership, and the hour with children and later life. Practitioners combine those positions with the relationships above when discussing a particular area of life. Different schools give different weight to strength, seasonal needs and these positional associations.

Birth pillars and changing luck

The birth chart remains fixed. To discuss changes over time, practitioners compare it with additional stem–branch pairs: those of individual years, often called liunian (流年), and a sequence of ten-year luck pillars, or dayun (大运). The luck-pillar sequence is derived from the month pillar; its direction and starting age are calculated separately. The first period does not automatically begin at birth or at age ten.

These changing pairs are read as supporting, restraining or otherwise altering the relationships present at birth. “Luck” here can describe favourable or difficult periods. The interpretation depends on how a period's pair interacts with the birth chart, rather than on its animal alone.

Time boundaries

Years and solar-term months

A common Bazi convention changes the year at the exact Lichun instant, rather than at Chinese New Year. The month changes at the instant of the relevant jie, one of the twelve solar terms that open these month intervals. These alternate with the twelve principal terms in the complete set of twenty-four solar terms.

Each interval below begins at its opening term and ends immediately before the next opening term. The terms do not have fixed Gregorian dates.

These intervals are distinct from the numbered lunar months of the lunisolar Chinese calendar. A leap month does not create a thirteenth solar-term month or restart the day cycle.

Days, hours and the clock basis

For a birth from 23:00 to just before midnight, one convention uses the next civil day's pillar; another retains the current civil day's pillar until midnight. Both recognise Zi, the Rat interval, corresponding to 23:00–01:00 in the modern double-hour table. The annual boundary and this late-Rat-hour rule are separate choices.

Zone-clock time and local solar time can also put a birth on different sides of an hour boundary. Apparent solar time follows the Sun's observed motion; mean solar time smooths its variation through the year. A chart using solar time requires conversion from a zone-clock birth record. Birth times and solar-term instants must be compared on a common time basis.

An unknown birth time leaves the hour pillar unspecified. On a date containing a relevant boundary, another pillar may also remain uncertain. Substituting noon or midnight would supply information the birth record does not establish.