The twelve earthly branches (地支)

The twelve branches at a glance

Three things in this table often surprise newcomers. The Bazi year starts with 寅 (Tiger), not 子 (Rat), because the first month is the one that begins at 立春. The 子 hour starts at 23:00 the previous evening, which creates the “late Zi hour” question discussed on our method page. And the element listed is only the branch’s main element: most branches also contain one or two secondary hidden stems.

Where the branches come from

Like the stems, the branches are ancient counting signs. San Ming Tong Hui quotes Cai Yong’s explanation of the word: “branch” means bough, and the branches are also called the twelve children of the ten stem “mothers”.

支，枝也。其名十有二，亦曰十二子，即今子丑寅卯辰已午未申酉戍亥是也。

““Branch” means bough. There are twelve of them, also called the twelve children; they are today’s Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai.”

— San Ming Tong Hui 《三命通會》, 卷一 · 论支干源流. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

(The Wikisource transcription writes 已 for 巳 and 戍 for 戌 in this line — common look-alike characters in old prints. We quote it exactly as transcribed.)

The association of the branches with twelve animals is the Chinese zodiac most people know. In Bazi the animal of the year branch is only one-eighth of the chart, and classical texts rarely use the animal names at all; they speak of the branches by their elements and their positions in the seasons.

Branches are not just “stems on the ground”

Classical authors insist that branches behave differently from stems. San Ming Tong Hui opens its chapter on the branches with exactly this point, and adds that a branch must be read according to its position — year, month, day or hour — with the month branch most important:

地支之用，不比天干，动静不同，圆方迥异。

“The use of the earthly branches is not like that of the heavenly stems: their movement and stillness differ, and they are as different as round and square.”

— San Ming Tong Hui 《三命通會》, 卷二 · 论地支. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

The Di Tian Sui chapter on branches begins with their polarity. Yang branches act quickly and visibly; yin branches act slowly, over years:

陽支動且強，速達顯災祥。

“Yang branches move and are strong: they bring fortune and misfortune quickly and visibly.”

— Di Tian Sui (Drops from Heaven’s Marrow) 《滴天髓》, 地支論. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

陰支靜且專，否泰每經年。

“Yin branches are still and concentrated: their ups and downs each take years to show.”

— Di Tian Sui (Drops from Heaven’s Marrow) 《滴天髓》, 地支論. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

The commentary lists the yang branches as 子 寅 辰 午 申 戌 and the yin branches as 丑 卯 巳 未 酉 亥.

The three groups of four

A very old way of grouping the branches is by their place in a season. Each season has a branch that begins it, one at its peak, and one that closes it and stores its energy:

• The four “growth” branches 寅 申 巳 亥 begin the seasons (spring, autumn, summer, winter).
• The four “peak” branches 子 午 卯 酉 sit at the solstices and equinoxes and are each dominated by one pure element (午 also hides a little 己 earth).
• The four “storage” branches 辰 戌 丑 未 end each season; they are earth branches that store the previous season’s element.

The Di Tian Sui says these groups react to clashes in opposite ways:

生方怕動庫宜開，敗地逄沖子細裁。

“Growth places fear being moved; storehouses should be opened; for the “defeat” places, judge a clash carefully.”

— Di Tian Sui (Drops from Heaven’s Marrow) 《滴天髓》, 地支論. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

寅申巳亥，四生也；忌衝動。辰戌丑未，四庫也；宜衝開。

“Yin, Shen, Si and Hai are the four growth branches: they should not be clashed. Chen, Xu, Chou and Wei are the four storehouses: they benefit from being clashed open.”

— Di Tian Sui (Drops from Heaven’s Marrow) 《滴天髓》, 地支論. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

Branches and the months

Each branch names a Bazi month. The month is not a lunar month but the stretch between two “jie” solar terms: 寅 month runs from 立春 (about 4 February) to 惊蛰 (about 6 March), 卯 month from 惊蛰 to 清明, and so on. This is why the month branch reliably tells you the season of birth, and why classical texts treat it as the most important single character in the chart after the Day Master. Yuan Hai Zi Ping calls the month the “governing axis” (提纲), and San Ming Tong Hui asks rhetorically how it could be taken lightly when the useful god is mostly taken from it:

况用神多取诸月，是月又可轻乎？

“Moreover, the useful god is mostly taken from the month — how then can the month be taken lightly?”

— San Ming Tong Hui 《三命通會》, 卷二 · 论年月日时. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

Branches and the hours

The day is divided into twelve double-hours, each named by a branch, starting with 子 at 23:00–01:00. In classical practice these are hours of local solar time — noon is the moment the Sun crosses the meridian — not hours on a modern time-zone clock. In Beijing the difference is small, but in western China, in Spain or on the western edge of any wide time zone it can exceed an hour, enough to move a birth into a different branch. See true solar time.

Relationships between branches

Much of Bazi interpretation concerns how branches interact. The main relationships are:

• Six combinations (六合): 子–丑, 寅–亥, 卯–戌, 辰–酉, 巳–申, 午–未.
• Three-branch combinations (三合): 申子辰 water, 亥卯未 wood, 寅午戌 fire, 巳酉丑 metal.
• Seasonal (directional) groups (方): 寅卯辰 east/wood, 巳午未 south/fire, 申酉戌 west/metal, 亥子丑 north/water.
• Clashes (冲): branches six places apart, such as 子–午 and 卯–酉.

Those relationships, with the classical explanations of each, are on the combinations and clashes page.

Your branches

The calculator shows your four branches with their animals, main elements and hidden stems, and flags births within fifteen minutes of a double-hour boundary, where a small error in the recorded time would change the hour branch.

Keep learning

More in Bazi basics, plus core guides — or go back to the Bazi calculator home page.

Classical quotations are copied from the public-domain texts on Wikisource; links let you check every line. English translations are our own. Traditional Bazi statements are reported as tradition, not as fact.