Snake in Chinese Astrology: The Sixth Branch, the Metal Born in Fire, and the Shadow of the Favor

The Favor That Bills

A woman found me last spring with a Snake-heavy chart. She was the one her family called. The deposit, the hospital run, the loan that was never quite a loan. She said she did not mind doing it. What she minded was that nobody seemed to notice, and that mentioning the cost chilled the room. I asked what she wanted. She wanted to be repaid, then heard the sentence and apologised.

That apology is the interesting part, and the classical texts named the mechanism two millennia ago.

What the Snake Is

The Snake (巳, si) is a yin Fire branch of the Chinese calendar, sixth of the twelve Earthly Branches. BaZi, the Four Pillars system built on that framework, reads it as one seat holding two titles, the office of yang Fire and the birth place of yang Metal.

It sits between the Dragon and the Horse, points south by southeast, opens summer, and holds the two hours 09:00 to 11:00 under the old name 隅中, nearing noon. Three stems live inside it: 丙 (bing), yang Fire, as the principal, 戊 (wu), yang Earth, and 庚 (geng), yang Metal, in residual. A generating chain sits in one branch, fire feeding earth and earth feeding metal, and it belongs among the four birth seats (生地) with the Tiger, the Monkey and the Pig.

Then there is the polarity. 巳 is a yin branch and every stem inside it is yang. The tradition has a phrase for the mismatch, 外陰內陽, yin outside and yang within, and a cool surface over a hot interior is the least surprising thing written about a snake.

The Branch Named Already

Shuowen Jiezi opens its entry on 巳 with two characters that work as both a definition and a joke, 巳也, si is already. 四月，陽氣已出，陰氣已藏，萬物見，成文章. In the fourth month the yang qi has already emerged, the yin qi has already gone into storage, and the ten thousand things appear and take on pattern. 段玉裁's commentary folds that picture into the calendar, 蛇，長而冤曲垂尾。其字像蛇，則象陽巳出陰巳藏矣. The character draws a long coiled snake, and drawing it is itself a picture of yang already out and yin already put away.

The Han compilers read the same character to three endings. 史記's 律書 links the branch to the month's pitch pipe and says 巳者，言陽氣之已盡也, the yang qi has already run out. 漢書's 律曆志 gives the opposite weather in six characters, 振美於辰，已盛於巳, at Chen the beauty shakes loose and at Si it is already at full. Two readings, one character, and they disagree about whether what is over is the work or the top of it.

A second story sits inside the same character. The older word for snake was 它, and the dictionary records the social consequence: 上古艸居患它，故相問無它乎. People in thatched shelters feared it, so they greeted each other with one question: no 它? No snake? The word later slid into the ordinary pronoun for it, leaving the animal to be rebuilt on the insect radical as 蛇. A greeting invented to check for one specific danger became the standard way of asking whether anything is wrong.

The Snake Years

The Snake Month

Zodiac months follow solar terms, not the calendar month's first day. The 2026 Snake month is 癸巳 (gui si), opening at 立夏 on May 5 and closing at 芒種 on June 5, the pair set by the month rule for a Bing year: 庚寅, 辛卯, 壬辰, 癸巳. 史記 pairs the branch with the pitch pipe 中呂, the note at which the ten thousand things turn west.

The hexagram for the fourth month is 乾 Qian, six firm lines and not one yielding line, the waxing year at its ceiling. The figure marking the maximum of yang is also where the first yin is seeded, since the next month is 姤 Gou, one yielding line entering at the base. A branch named already and a hexagram meaning full describe the same instant. Hexagram 1, The Creative carries that figure.

The Palace

The twelve sky divisions give the Snake the station 鶉尾, the Quail's Tail. 天原發微 states it in four characters, 鶉尾會巳. Its first lunar mansion, 翼火蛇, carries the animal's own name in its own element, one of only two branches where the palace animal matches the sign's own. The other is the Rabbit, whose mansion 房日兔 had an earlier post in this series.

What the Snake Touches

Against the rest of the ring, the count comes out strange. 巳申合化水, the six combination with the Monkey, which transforms into water. 巳酉丑, the three-harmony metal formation, where the Snake holds Metal's birth and the Rooster and Ox complete the group. 巳午未, the southern fire quarter. 巳亥, the clash with the Pig. 寅巳, the six harm with the Tiger. 巳申 again among the six breakages, 寅巳申 among the three punishments. The full list is on this reference table.

So the Snake carries three relations to the Monkey, a combination, a punishment and a breakage, and two to the Tiger. No other branch doubles every relationship. 三命通會 opens its chapter on the three punishments with 恩生於害，害生於恩, favor born from injury and injury from favor, since the punishments come from the pairings the way the harms come from the unions. The next line reads like clinical notes: 合中生刑，猶人夫婦相合而反致刑傷, a punishment inside a combination, like a married couple whose union produces its own injury.

A caveat on the breakage, the weakest theory of the six. It is read as same-group pairs that unsettle the six clashes, and the publisher 聚賢館 notes that the dominant 子平 school skips it. I keep it because dropping it would hide that the Snake's most loaded relationship carries three labels at once.

The Shadow of the Favor

五行精紀, a Song collection, keeps the oldest explanation of the punishment of ingratitude, quoting the 玉霄寶鑑: 寅有生火，刑巳上生金，巳上有寄生之土，刑申之水，申中生水，刑寅中生火，不恤所生，遙相克制，故曰無恩刑. Each makes one element and injures what the next makes. The Snake carries an earth living in it as a guest, and that earth injures the water in the Monkey. Nothing has pity for what it produced, and each destroys its own product from a distance. That is why the punishment is called ingratitude. Source: Chinese Text Project.

One more line there is worth keeping. 巳中之丙，刑申中之庚: the yang Fire living inside the Snake injures the yang Metal sitting inside the Monkey. Compare 三命通會's note that 巳中有土，能生金，金既長生，又自坐祿: the earth inside the Snake generates metal, and the metal is born there and seated on its own office. The branch births the metal and turns on it, which is what 施恩反辱 says, the favor given coming back as insult.

Carl Jung offered the psychological translation. In Psychology and Religion he wrote that everyone carries a shadow, that the less it is embodied in a conscious life the blacker and denser it grows, and that it forms an unseen snag thwarting our best intentions. Those last four words are the Snake's file. Anyone who builds an identity on being the one who gives has put their own need out of sight, since the role of the giver has no room for wanting. It surfaces later as an account, and an account nobody agreed to reads as a trap. The insult is the sound a hidden ledger makes when it speaks.

Working With a Snake Chart

Write the ledger. List five things you did for someone this month and what you expected back, including what you never said aloud. Column two is where the punishment lives.

Name the blade. Name one thing you are building, then the part of it that could be turned on you. The Snake's hidden stem is metal, born in its heat and injured by the same heat.

Close one account. The branch is named already. Pick one finished thing and stop attending to it for a week.

Journal prompt. Write the sentence you would say if you knew it would land well, and notice the missing word.

What She Said

She came back in the autumn. She had told her brother the number, in a sentence with no apology in it. He paid part of it, late, with a comment that stung.

What she reported was this. The comment mattered less than the decade of not asking. The account was visible, and the gift could go back to being one.

This article is offered for spiritual guidance and entertainment purposes only. It is not a substitute for medical, legal, or financial advice.