The twelve earthly branches
The bottom character of every pillar is a branch (地支, ). There are twelve, and you already know them by another name: the twelve animals of the Chinese zodiac. In BaZi, though, a branch is more than an animal. It's a season, a time of day, and a small store of stems kept inside.
The animals and their seasons
The branches go around the year like the hand of a clock. Each one runs a BaZi month, starting with the Tiger at , the Start of Spring, around February 4.
- Spring: 寅 Tiger (Wood), 卯 Rabbit (Wood), 辰 Dragon (Earth).
- Summer: 巳 Snake (Fire), 午 Horse (Fire), 未 Goat (Earth).
- Autumn: 申 Monkey (Metal), 酉 Rooster (Metal), 戌 Dog (Earth).
- Winter: 亥 Pig (Water), 子 Rat (Water), 丑 Ox (Earth).
Each season has two branches of its own element, and then closes with an Earth branch. Those four Earth animals, the Dragon, the Goat, the Dog and the Ox, are the turns between seasons. Think of the days when you can feel the weather starting to change.
BaZi months don't run from the 1st to the 31st. Each starts at a solar term, somewhere between the 4th and the 8th of the calendar month. So the Tiger month runs from about February 4 to about March 6.
And the hours of the day
The same twelve also split the day into two-hour stretches. The Rat runs from 11 pm to 1 am, the Ox from 1 to 3 am, the Tiger from 3 to 5 am, and so on around until the Pig, from 9 to 11 pm. By default the app measures these hours by the Sun in your birth city, not by the clock. That's why your Hour pillar can differ from what a quick look at the clock would suggest.
Your year animal
The branch of your Year pillar is the animal people mean when they say "I'm a Horse" or "I'm a Rabbit". In BaZi it changes at , not at Chinese New Year. So if you were born in January or early February, your animal may be the previous year's.
But your chart has four animals, not one. Each pillar brings its own: year, month, day and hour. The one in your Day pillar sits right under your Day Master, like the ground it stands on. The tradition also reads it as the place of your partner in the chart.
Yang and Yin animals
The branches take turns, just like the stems. The Rat is Yang, the Ox Yin, the Tiger Yang, the Rabbit Yin, and so on around. A Yang branch only ever pairs with a Yang stem, and a Yin branch with a Yin stem.
What's inside a branch
A stem stands alone. A branch carries one, two or three stems inside, like seeds in the soil. They're called hidden stems, and they count in the reading too. The first one is the main stem, the heart of the branch.
- 子 Rat: 癸
- 丑 Ox: 己 癸 辛
- 寅 Tiger: 甲 丙 戊
- 卯 Rabbit: 乙
- 辰 Dragon: 戊 乙 癸
- 巳 Snake: 丙 庚 戊
- 午 Horse: 丁 己
- 未 Goat: 己 丁 乙
- 申 Monkey: 庚 壬 戊
- 酉 Rooster: 辛
- 戌 Dog: 戊 辛 丁
- 亥 Pig: 壬 甲
Look at the four Earth animals. Each keeps a little of the season that's ending, like a pantry after the harvest. The Dragon holds a last drop of winter Water, the Goat a bit of spring Wood, the Dog a spark of summer Fire, and the Ox a piece of autumn Metal.
To see them for your own chart, tap any pillar on the Chart tab and look under "Hidden stems".
Branches meet each other
Some branches are drawn together, like the Rat and the Ox. Some sit opposite each other on the circle, like north and south: the Rat and the Horse, the Tiger and the Monkey, the Rabbit and the Rooster. The tradition calls the first a combination and the second a clash. A clash is read as movement, tension or change, not as bad luck. The app looks for these between your own pillars, between your chart and the years that come, and between two people.
In plain words
A branch tells you where you are in the year and in the day, and what's stored underground at that moment. The animal is the easy way to remember it. What it holds inside is where much of the reading happens.