Stems & Branches

Hundreds of thousands of people share your zodiac animal, yet sharing it settles almost nothing about a chart. Your animal is one character out of eight — and long before it was an animal, it was a mark for counting days.

This article asks one question. If so many people share an animal, why does that not make their charts the same? To answer it, we have to look at what the ten Heavenly Stems and twelve Earthly Branches — twenty-two characters in all — originally were.

The short answer: twenty-two marks for time

A Saju chart writes your birth year, month, day, and hour as two characters each — eight in all. The ten characters used on the top row are the Heavenly Stems; the twelve used on the bottom row are the Earthly Branches. Twenty-two characters, and that is the entire alphabet.

The order matters. These characters were not invented to sort people; they were invented to count days, and reading people with them came afterward. If the layout is new to you, start with the Saju introduction to see where the eight characters sit.

They were not called Stems and Branches

The Lü Shu (Treatise on Pitch-pipes) in Sima Qian’s Shiji does not use the words Heavenly Stem or Earthly Branch. It calls the ten characters the Ten Mothers and the twelve the Twelve Children — two sets of marks that pair off and roll forward together.

The older dictionary Erya records different names again. Each Stem has a “year-yang” name (Gap is Albong, Eul is Jeonmong) and each Branch a “year-yin” name (Gondon, Jeokbunyak). Not an animal in sight. They were labels for counting years.

What the ten Stems originally meant

The Lü Shu assigns the Stems to the winds of each direction and glosses them one by one. Every gloss describes sprouting, growing, ripening, and storing — never a temperament. Gap 甲 is things splitting the husk and pushing out; Eul 乙 is growing with a creaking strain; Byeong 丙 is the way of yang turning plainly bright; Jeong 丁 is things coming into full vigor.

Turn toward autumn and the tone shifts. Gyeong 庚 is yin qi altering all things; Sin 辛 is things emerging newly and sharply; Im 壬 is sustaining and nourishing from below; Gye 癸 is becoming measurable at last. A full turn of the year sits inside ten characters.

One point is worth flagging. Mu 戊 and Gi 己 do not appear in this passage. The Lü Shu distributes the Ten Mothers across the winds of east, south, west, and north — which leaves the two characters belonging to the center outside the scheme. We could fill the gap from another text, but this article leaves absent what is absent.

Two faces of one element

The ten Stems pair up and share the five elements between them: Gap and Eul are Wood, Byeong and Jeong Fire, Mu and Gi Earth, Gyeong and Sin Metal, Im and Gye Water. The first of each pair is yang, the second yin — the same element with a different grain.

• Gap 甲 · Wood · Yang — splitting the husk and pushing out
• Eul 乙 · Wood · Yin — growing with a creaking strain
• Byeong 丙 · Fire · Yang — the way of yang turning plainly bright
• Jeong 丁 · Fire · Yin — things coming into full vigor
• Mu 戊 · Earth · Yang — absent from this passage of the Lü Shu
• Gi 己 · Earth · Yin — absent from this passage of the Lü Shu
• Gyeong 庚 · Metal · Yang — yin qi altering all things
• Sin 辛 · Metal · Yin — things emerging newly and sharply
• Im 壬 · Water · Yang — sustaining and nourishing from below
• Gye 癸 · Water · Yin — becoming measurable at last

If the way elements feed and check one another is unfamiliar, keep the Five Elements guide open alongside. Among these ten, the Stem of your birth day — the Day Master — becomes the reference point for the whole reading.

What the twelve Branches originally meant

The Branches work the same way. Ja 子 means swelling from below; In 寅 is things first wriggling into being; Myo 卯 is turning luxuriant; Yu 酉 is growing old; Sul 戌 is being extinguished. Read the twelve in order and you get one year being born, growing, ripening, and fading.

In the table below, read the second column against the last one. The original meanings and the animals have nothing to do with each other.

The blank on the Chuk 丑 row is not an oversight. In the transmitted text the twelfth-month passage names Chuk and then simply stops; no gloss follows. Other books do gloss it, but quoting them as though they were the Lü Shu would be a different claim.

When the animals arrived

The earliest systematic pairing of Branches with the animals we know today appears in the Lunheng of Wang Chong, Eastern Han. Its “Wu Shi” chapter states: “In 寅 is Wood, and its beast is the tiger. Sul 戌 is Earth, and its beast is the dog… Hae 亥 is Water, and its beast is the pig.”

What deserves more attention is why he wrote it down. Wang Chong brings in the animals to test the claim that the five elements conquer one another — “Wood conquers Earth, therefore the dog, ox, and goat submit to the tiger.” The animals were not there to explain what a Branch means. They were illustrations recruited to make elemental conquest visible.

So what can a zodiac animal actually tell you?

Your animal is the Year Branch — one character, the lower half of your year pillar. It is not your chart. The other seven characters vary with the month, day, and hour of birth, and sharing an animal determines none of them.

So “I am a Tiger, so I am like this” leans on one character out of eight, and on a nickname rather than that character’s meaning. The animal is a useful doorway into knowing which characters your chart holds. It is not a basis for settling personality, compatibility, or career.

Branches have Stems inside them

Here is where Branches differ decisively from Stems. A Branch is not hollow. Each of the twelve conceals one to three Stems inside it — the Hidden Stems.

Two charts can hold the same Branch and still read differently depending on which Hidden Stem is actually doing the work. Counting only the surface element erases that whole layer. The method for reading inside a Branch continues in the Hidden Stems guide.

Stems and Branches do different jobs

In practice the two are never read apart. Year, month, day, and hour each form one pillar of an upper and a lower character, so you check whether the Stem above has a root in the Branch below. That is also why an uncertain birth time destabilizes the entire hour pillar — see why birth time matters.

Why twenty-two characters make sixty pairs

Now back to the arithmetic. Pair ten above with twelve below and you would expect 120 combinations. Only sixty are ever used.

Yang pairs only with yang, and yin only with yin. Gap (yang) pairs with Ja (yang); Eul (yin) pairs with Chuk (yin). A mismatched pair like Gap with Chuk is simply never formed. That halves 120 to sixty — the sexagenary cycle — which lands exactly on the least common multiple of 10 and 12.

As a footnote, the polarity of Ja, O, Sa, and Hae is written differently across lineages depending on how substance and function are weighed. For laying out the sixty pairs, though, the alternating order is the working standard.

Where the sixty pairs actually land

The sixty cycle turns over years, months, days, and double-hours alike, so each of the four pillars carries one pair. The pair for your birth day is the Day Pillar, and Ziping-tradition reading weights that position most heavily.

The sixty Day Pillars are taken one by one in the sixty Day Pillars guide, and how the characters of a year or month generate a flow continues in the Twelve Stages.

What happens when characters meet

The eight characters do not simply sit side by side; they pull at and collide with one another. Two may bind and change character (combination), or strike head-on (clash), along with punishment, destruction, and harm.

These interactions carry enough conditions that summarizing them here would mislead more than it helps. The rules for each combination live in a dedicated article — combinations, clashes, and the rest.

Four sentences for reading your own chart

1. “Can I write my eight characters as four on top and four below?”
2. “Which character is the Stem of my birth day — my Day Master?”
3. “Where does my zodiac animal sit among the eight, and what are the other seven?”
4. “Which Hidden Stems sit inside each of my four Branches?”

Once those four are written down, the frame shifts from “I am a Tiger” to “my chart is made of these characters.” That shift is where reading Saju begins.

One sentence to keep

Open your own chart and read it in two rows — four Stems above, four Branches below — then find where the Year Branch behind your zodiac animal sits among the eight.

See My Eight Characters

Sources and how the evidence was handled

The original names (Ten Mothers, Twelve Children) and the per-character glosses come from the Lü Shu of the Shiji; the animal-free older names (year-yang and year-yin) from the “Shi Tian” chapter of the Erya; the first systematic Branch-to-animal listing from the “Wu Shi” chapter of the Lunheng — each read in the original. That ganzhi were already used to date days in the Shang oracle bones is taken from published archaeological summaries.

Four things are deliberately not claimed. First, who created the ganzhi and when: the Yellow Emperor attribution is legend, and what can be established is only that the system was already in use by the oracle-bone period. Second, the Lü Shu glosses are Han-era interpretation, not the meaning the characters carried when they were first made. Third, Mu, Gi, and Chuk are left blank rather than filled in from other texts. Fourth, the polarity of Ja, O, Sa, and Hae is given only as the ordering convention, since lineages differ.

Classical lines are quoted and the explanations rewritten. This article does not use a zodiac animal or a Stem to settle personality, compatibility, career, or health, and does not present the sixty-year cycle as a cycle of destiny or a prediction. The fixed personality table for the ten Stems that appeared in the earlier version has been removed, as it turned lineage-specific readings into flat assertions.