The Four Pillars

Your birth information gets broken down into four points in time:

Each pillar is made up of two characters: a Heavenly Stem on top and an Earthly Branch on the bottom. Two characters per pillar, four pillars — that's eight characters total. That's where the name Bazi (八字) comes from: "eight characters."

The Heavenly Stem and Earthly Branch of each pillar represent different energies — one of the five elements in a Yin or Yang form. But don't worry about decoding those yet. That's what the next page (Heavenly Stems & Earthly Branches) is for. For now, just understand the structure.

Each pillar doesn't just represent a point in time — it maps to a different part of your life and a different stage of it.

Year Pillar (年柱)
This is the pillar most people already know, since it determines your zodiac animal. It represents your ancestry, your family background, and the environment you were born into. It speaks to the outermost layer of who you are — how the world first sees you, your roots, and the social conditions around your early years. In terms of life stages, it covers roughly ages 1 to 16.

Month Pillar (月柱)
Often considered the second most important pillar after the Day Pillar. The Month Pillar represents your parents, your upbringing, and the conditions of your youth. It also reflects your career potential and how you engage with society. It's closely tied to the season you were born in, which has a big influence on the strength of your chart. It covers roughly ages 17 to 32.

Day Pillar (日柱)
This is the heart of the chart. The Day Pillar — specifically the Heavenly Stem on top of it — is called the Day Master, and it represents you. Your core self. Everything else in the entire chart is read in relation to this one character. The Earthly Branch underneath represents your spouse or closest partner. The Day Pillar covers roughly ages 33 to 48, and the Day Master is so important that it gets its own full page later in this guide.

Hour Pillar (时柱)
The Hour Pillar represents your children, your later years, and your inner aspirations — the things you want to achieve or leave behind. It's the most personal and private pillar, pointing to what drives you beneath the surface. It covers ages 49 onward.

Here's what a Bazi chart looks like in practice. This is a hypothetical example — not a real person — just to show you the layout:

Reading from left to right, you can see four columns — one for each pillar. At the top of each column is the Heavenly Stem, and at the bottom is the Earthly Branch. Each one carries an element and a polarity (Yin or Yang), and each Earthly Branch corresponds to one of the twelve zodiac animals.

In this example, the Day Master is 丙 (Bing) — Yang Fire. That's the central reference point for the entire chart. Everything else — the Water in the Year, the Wood in the Month, the Metal in the Hour — gets interpreted based on how it relates to that Fire Day Master.

Don't worry if that doesn't make full sense yet. It will once you've read through the Day Master and Ten Gods pages.

This is the key difference between casual Chinese astrology and Bazi. When someone says "I'm a Dragon," they're only talking about their Year Pillar. That's one-quarter of the picture. It's like reading the first chapter of a book and thinking you know the whole story.

Each pillar adds a new dimension. Your Year Pillar might say one thing about you, but your Month Pillar could shift that meaning significantly. Your Day Pillar reveals who you actually are at the core, and your Hour Pillar shows where you're heading. The four pillars together create a much more complete and personal picture than any single one could on its own.

This is also why two people born in the same year — both Dragons, for example — can have very different personalities and life paths. Their Year Pillar is the same, but the other three pillars are likely completely different.