Hour Stem Table for Yi 乙 Day: All 12 Hour Pillars

For a Yi 乙 (Yǐ) day pillar, this is the bazi hour stem table for Yi day — the twelve double-hours matched to clock times and their complete hour pillars. Yi is yin Wood, the vine and the grass: pliant, reaching, quietly persistent. Its day opens on the Rat hour 丙子, so the first stem of the day is 丙 Bing, Fire drawn out of the soft Wood.

The 12 hour pillars for a Yi 乙 day

Worked example

Take a Yi day birth at 06:10. Six-ten falls in the Rabbit hour (卯, 05:00–06:59), so the hour pillar is 己卯 (Jǐ Mǎo). The branch 卯 is itself yin Wood — the same element as the Yi Day Master — so this chart carries a doubled-Wood signature in its final pillar, something a reader would weigh when judging the chart’s strength.

Go one layer deeper and the pillar opens up further. The Rabbit branch hides a single stem — Yǐ 乙 (Yin Wood) — so the Day Master finds a root of its own kind in the hour, exactly the anchoring a soft Yi stem values. Meanwhile the visible stem 己 is Earth, which Yi Wood controls: Indirect Wealth 偏财 for this Day Master, per the ten gods (十神 shíshén) table. Wealth on the surface, self underneath — the sort of tension a reading spends time on. Hidden stems for every branch are on the hidden stems table.

Ten gods across a Yi day’s hours

Since the Day Master is fixed, each stem in the column above carries a definite ten god for Yi. The day opens on output — 丙 is Hurting Officer 伤官 and 丁 is Eating God 食神, the two talent gods, colouring the Rat and Ox hours. The Tiger and Rabbit hours seat wealth: 戊 is Direct Wealth 正财 and 己 is Indirect Wealth 偏财. Mid-morning through noon turns to power — 庚 is Direct Officer 正官 on the Dragon hour, 辛 is Seven Killings 七杀 on the Snake. The Horse and Goat hours bring resource, with 壬 as Direct Resource 正印 and 癸 as Indirect Resource 偏印. The Monkey hour’s 甲 is Rob Wealth 劫财, the Rooster hour’s 乙 is Friend 比肩, and then 丙 and 丁 return for the Dog and Pig hours. Whichever block holds your birth time, that god sits in the hour palace — the seat of children, output and later life — and sets the tone of the chart’s final chapter.

Reading the pattern, and reading the clock

Two things are worth noticing before you lift a pillar off this table. First, the pattern itself: as you move down the hours the branch stays fixed by the clock, but the stem climbs one step of the ten-stem sequence at every hour, looping from 癸 back to 甲 when it reaches the end. That single motion is the whole Five Rats rule at work, and it is why the Yi-day column begins on 丙子 and closes twelve steps later on 丁亥.

The rule itself is compact: hour stem index = (day-stem-index mod 5) × 2 + hour-branch-index, mod 10. Day stems pair — 甲/己, 乙/庚, 丙/辛, 丁/壬, 戊/癸 share columns — which is why this Yi table is identical to the Geng day hour table: 乙 and 庚 both send the Rat hour to 丙子.

Second, the clock. The times above are true solar times, tied to the sun’s real position rather than the figure on a birth certificate. Two corrections can push a birth across an hour line. One is the longitude gap between the birth city and the meridian its time zone is officially set to — 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 other is the equation of time, a seasonal drift of up to about a quarter-hour either way. For a Yi-day birth logged near a boundary such as 10:56, those few minutes decide which row above is genuinely yours. The calculator linked below applies both corrections for you, which is why its result can differ from a hand count taken off raw clock time.

The late Zi (子) note for Yi days

The Rat hour spans 23:00–00:59 and crosses midnight. A birth from 23:00–23:59 on a Yi day takes the next day stem’s Zi pillar for the hour, while the day pillar stays Yi. This is the late-Zi (晚子時 wǎn zǐshí) convention; schools honestly disagree, and the reasoning is set out on the birth hour and hour pillar page.

When the hour is missing

Plenty of Yi-day charts arrive with no recorded time at all. Do not discard the reading: the day, month and year pillars still fix the Day Master, the season that decides its strength, and the luck cycles. What the missing hour removes is the destination palace — children, output, later life — and its ten god. In practice we work in this order. First, documents: birth certificates and hospital notes are more often time-stamped than families remember. Second, story: a parent who says “the grass was still wet, before breakfast” has narrowed twelve branches to one or two. Third, testing: because Yi’s hours run in clean ten-god blocks, candidate hours differ sharply — a 辛巳 hour seats Seven Killings where a 壬午 hour seats Direct Resource — and matching those signatures against a lived life usually settles the question. Cast each candidate and compare rather than guessing once and trusting it.

What the hour pillar governs

As the destination pillar, the hour speaks to children, output and the later stretch of the road — ambition and legacy rather than origin. Because it is computed from the day stem through the Five Rats rule (五鼠遁 wǔshǔdùn), it pays to see the whole system at once on the master hour stem table. Its yang-Wood sibling, the Jia day hour table, starts its Rat hour on 甲子 — a useful contrast to Yi’s 丙子 opening.

Rather not count by hand? Plot your Yi-day chart free with the calculator and read your hour pillar to the minute.