The Four Pillars (四柱)
Four columns that are read as one chart.
In short
The four pillars (四柱, sì zhù) are the year, month, day, and hour of birth, each written as one heavenly stem over one earthly branch. They are not four separate readings. The day pillar is the reference point, and the other three are interpreted in relation to it.
| Characters | 四柱 · 八字 |
|---|---|
| Pinyin | sì zhù |
| Group | Building the chart |
Each pillar covers a stretch of life and a set of concerns. The year pillar is the earliest years and the wider environment a person arrived in, the month pillar is parents and career and carries the most weight of the three outer pillars, the day pillar is the person and their closest relationship, and the hour pillar is children, output, and the later decades.
The pillars do not change over on the dates you might expect. The year turns at Start of Spring near 4 February. The month turns at the jie solar terms, roughly the 4th to the 8th of each month, so a chart month is a day or two off the calendar month at both ends and can start in the previous month entirely.
The day pillar turns at midnight, or at 23:00 depending on the school, which is a live disagreement rather than a settled point. The hour pillar turns every two hours, read in true solar time at the birth location.
Reading order matters more than most introductions admit. The day master is established first, since every other character is named relative to it. The month branch comes next, because the season decides how strong the day master is. Only then does the rest of the chart get read, and a chart read in a different order tends to produce a different answer.
Definitions get you through a chart. Something has to be done with it.
The audit walks the nine areas of a home in the order that matters, with two or three changes per area. It is the practical half of what these terms describe.
Questions people ask about this term
Which pillar matters most?
The day pillar. Its stem is the day master, the character that stands for the person, and every other character gets its meaning from how it relates to that one. The month branch is second, because the season it records decides whether the day master is strong or weak.
Why does the year pillar change in February?
Because Bazi uses the solar year, which begins at Start of Spring near 4 February, rather than the calendar year or the lunar new year. Anyone born in January or the first days of February belongs to the previous year pillar, which is the single most common error in charts produced by general AI tools.
Can a chart be read without the hour pillar?
Partly. You lose the hour pillar and with it the later-life and output positions, leaving six characters. The day master and the element balance still stand, so a rough reading is possible, but the hour is what separates charts that otherwise look identical.
This page has no affiliate links and nothing to sell. The tables here are fixed by the tradition and you can check any of them against a printed almanac. What a chart means for a person is a reading of that tradition, not a finding, so treat it as a way to think about a situation rather than a prediction.