Chart anatomy · 四柱

Four Pillars, eight visible characters

A chart is four paired coordinates for one birth moment. Each pillar places a heavenly stem above an earthly branch; the day stem becomes the reference from which the rest of the chart is read.

Build your four pillars
Four inscribed chart tablets in a Chinese observatory pavilion at the turn from night to dawn
Four paired tablets mark year, month, day and hour; the cinnabar day tablet is the chart's reference point.

One moment, four scales

What each pillar contributes

All four pillars have the same two-character construction. Their difference is the scale of time they locate: year, solar month, day and two-hour period.

  1. 01

    Year pillar

    The chart's annual coordinate

    The year pillar changes at Li Chun in Four Pillars practice. Its branch is also an animal, but this chart coordinate is not always the same as the familiar Chinese New Year animal year.

  2. 02

    Month pillar

    A solar month, not a lunar month number

    Each chart month opens at one of the twelve Jie solar terms. The month branch follows a fixed Tiger-to-Ox sequence, while the month stem is derived from the year stem.

  3. 03

    Day pillar

    The chart's reference point

    The day stem is called the Day Master. Every other visible stem—and every hidden stem inside a branch—is named by its phase and polarity relationship to this one stem.

  4. 04

    Hour pillar

    One of twelve two-hour positions

    The hour branch changes every two hours. Its heavenly stem is paired from the Day Master and that branch, so a birth time adds a complete fourth pillar rather than an animal label alone.

The year has two useful doors

Chinese New Year and Li Chun answer different questions

The site keeps both results visible because the popular animal year and a Four Pillars year can turn on different dates.

春节

Chinese New Year

Outer animal year

The first day of the first lunar month begins the familiar zodiac year used for the outer-animal result.

立春

Li Chun

Four Pillars year

The Start of Spring solar term turns the chart's year pillar and opens the Tiger month.

See dates, examples and the full boundary guide
日主Day Masterthe day's heavenly stem

The centre of the reading

Why the day stem matters

The Day Master is not a fifth pillar. It is the visible stem already sitting in the day pillar, promoted to a special job: it becomes the point of comparison for every other stem in the chart.

First compare the five phases: same, generated by, generating, controlling, or controlled by. Then compare yin and yang. Those two facts produce the chart's Ten Gods names.

What the characters reveal

Visible stems, visible branches—and stems inside branches

The written chart starts with eight characters. A complete structural reading can then open each branch and inspect the stems it carries within it.

8

Visible characters

Four heavenly stems above four earthly branches.

Hidden stems

Each branch contains one, two or three stems in a fixed order.

10

Relationship names

Every visible and hidden stem can be read against the Day Master.

Open the twelve-branch hidden-stem atlas