The si hour in bazi is the Snake hour (巳 Sì), 09:00–10:59 — mid-morning, when the ground has warmed enough for the snake to leave its hollow and lie in the strengthening sun. In element terms 巳 is Fire: bright, quick, and precise. It is the hour of sharp focus, of intelligence turned outward onto the day’s real work.
The Snake hour (巳) and its time range
Si is the sixth Earthly Branch, Fire on the rise but not yet at its peak. Its character is discernment — the snake watches, calculates and strikes only when the moment is exact. There is elegance and reserve in the Snake hour, warmth held under control rather than blazing freely.
The Snake hour pillar by day stem
The stem on 巳 follows from the day stem through the Five Rats rule (五鼠遁 wǔshǔdùn):
| Day stem | Snake hour pillar |
|---|---|
| 甲 Jiǎ | 己巳 |
| 乙 Yǐ | 辛巳 |
| 丙 Bǐng | 癸巳 |
| 丁 Dīng | 乙巳 |
| 戊 Wù | 丁巳 |
| 己 Jǐ | 己巳 |
| 庚 Gēng | 辛巳 |
| 辛 Xīn | 癸巳 |
| 壬 Rén | 乙巳 |
| 癸 Guǐ | 丁巳 |
Locating the Snake hour in a chart
Practical first: cast your chart and read the hour pillar’s lower character. If it shows 巳, your birth fell in this 09:00–10:59 window, and the upper character should agree with your day stem’s row above — a Ding or Ren day gives 乙巳, a Jia or Ji day gives 己巳, and so on. If the stem on the printout disagrees with your hand count, the software has almost certainly applied a solar-time correction and shifted the effective hour; that is a feature, not a fault. The reading-order guide shows where the hour pillar sits among the four and why it is read last.
What 巳 hides, and the ten gods it seats
Beneath the visible stem, the Snake carries three hidden stems (藏干 cánggān): Bǐng 丙 (Yang Fire), Wù 戊 (Yang Earth), Gēng 庚 (Yang Metal). Fire is the main qi (本气 běnqì); Earth and Metal ride underneath — which is why 巳 behaves as more than a simple Fire branch, holding a seed of the Metal season inside the Fire hour. Each hidden stem becomes a ten god (十神 shíshén) against your Day Master. For a Xin 辛 Day Master the Snake hour is a quietly complete destination: 丙 is Direct Officer 正官, 戊 is Direct Resource 正印 and 庚 is Rob Wealth 劫财 — position, protection and peers layered in one palace. For a Jia 甲 Day Master the same branch reads as 丙 Eating God 食神, 戊 Indirect Wealth 偏财 and 庚 Seven Killings 七杀: talent producing gain with pressure buried under it. The full mapping for every branch is on the hidden stems table.
What being born in the Snake hour colours
The hour is the destination pillar — children, output, ambition and later life. Rising Fire at that destination reads as bright, targeted expression: people whose later chapters run on intelligence and timing, who prefer the well-aimed move to the loud one, and who often keep their true reasoning private. The Snake hour carries a refined, strategic warmth and a taste for quality. It can tip into secrecy or coolness if the chart lacks openness elsewhere. As always, the effect is settled by the balance of the whole reading.
Clock time, solar time and the Snake boundary
The window given for the Snake hour, 09:00–10:59, is true solar time — pinned to the sun’s actual position rather than the number printed on a birth certificate. Two corrections can carry a birth across the edge of this hour. The first is longitude: a birth city rarely sits exactly on the meridian its time zone is set to, and in Singapore, where clocks run on UTC+8 while the island lies nearer 104°E, civil time can lead solar time by close to half an hour. The second is the equation of time, a seasonal wobble of up to about a quarter-hour in either direction.
Near either edge of the Snake hour those minutes are not cosmetic. They can move a chart into the hour before or after, and with it a different hour pillar and a different final reading. This is the quiet adjustment that separates a rough chart from an accurate one, and it is why a birth time known only to the nearest hour always deserves a second look before its hour pillar is trusted. If your recorded time sits within twenty minutes of 09:00 or 11:00, treat the neighbouring hour as a live possibility until the solar correction is done; the calculator linked below makes both corrections automatically.
When no one wrote the time down
An unknown birth hour does not void the chart — Day Master, season and luck pillars all come from the other three pillars — but it does blank the children and later-life palace. Recover it methodically. Documents beat memory; ask for the birth record before polling the family. If memory is all there is, tie it to the morning’s routine: “after the market, before lunch” points at 巳 far more reliably than a guessed clock figure does. Then test. The Snake hour’s layered hidden stems give it a distinctive signature — if the alternative candidate is the Horse hour, the destination changes from Fire-holding-Metal to pure blaze, and charts this different tend to sort themselves out against a real biography. Cast both, live with each for a week, and note which one keeps being right.
Fixing your own Snake hour
The hour pillar is derived, never taken off a calendar. To see 巳 among all sixty hour pillars, use the master hour stem table; the neighbouring Horse hour page carries the morning into noon. For hour boundaries and the late-Zi (晚子時 wǎn zǐshí) convention, see the birth hour and hour pillar page. Or plot your chart free with the calculator and read your hour pillar to the minute.