BaZi day master · 1 of 10
Yang Wood Day Master (甲木) in BaZi
甲 is yang wood — the tall tree. It is read as growth that has already chosen a direction: structure, principle, and a preference for going straight through an obstacle rather than around it. If your day pillar begins with 甲, this is the one character every other part of your chart is measured against.
The short version
甲 is wood at its most structural — a trunk, not a vine.
A day master is a starting point, not a verdict. 甲 is one character out of eight, and the other seven decide how it reads.
Is your day master 甲?
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Enter your birth date — nothing else is required for this answer. If the result comes back with a different stem, the profile for it is one click away at the bottom of the page.
How it’s calculated
- 1
Take the day pillar
The day pillar advances exactly one step per calendar day with no gaps and no leap corrections. That continuous count is what makes it reliable: it does not depend on the calendar reform, the timezone or the season.
- 2
Read its heavenly stem
The stem of that pair is the day master. 甲 is the 1st of the ten stems, so “is my day master 甲?” reduces to one question about one character — and it can be answered from the date alone.
- 3
Set it as the reference
Once 甲 is fixed, the other seven characters stop being a list and become relationships. Every stem in the chart is named by how it stands to 甲 — that is the table on this page, and it is different for each of the ten stems.
The full rule set — every convention, in order, with the engine field names — is published on the methodology page.
What 甲 means as a day master
There are ten heavenly stems and 甲 is the first. Each stem fixes an element and a polarity, and 甲 is wood at yang: the tree, the beam, the upright trunk. The classical image is not decoration — it is a compression of behaviour. A tree grows upward and outward at the same time, it needs ground it can stay in, and it does not bend to accommodate a wall.
Wood has two stems and the contrast between them is deliberate. 乙 is the vine and the grass, which survives by taking whatever route is already open. 甲 does not work that way: faced with a wall it goes over or through, and the classical reading is that it would rather be cut than curve. That is the trade-off inside the image — the same inflexibility that reads as integrity also reads as stubbornness, depending on what the rest of the chart does with it.
The ten gods, read from 甲
The ten gods are not ten things — they are five relations, each of which comes in two polarities, and the relation is always measured from the day master. With 甲 as the reference the five relations resolve as follows: 木 itself is the Peer, Water generates 木 and is the Resource, Fire is what 木 produces and is the Output, Earth is what 木 controls and is the Wealth, and Metal is what controls 木 and is the Officer.
The table below is produced by the engine from that rule alone — the element relation, multiplied by whether the two stems share a polarity. Nothing in it is memorised and nothing in it is interpreted. This is the reason a chart can be re-read by anyone: change the day master and all ten names change at once, in a way that is checkable rather than a matter of opinion. On the chart in the worked example below, 甲 is the day stem itself, so the four visible stems around it each carry one of these names.
What feeds 甲, and what spends it
A chart is not read by counting elements — it is read by what each element does to the day master. Water (壬 癸) generates 木, so it is the Resource: what supplies 甲 without being asked. 甲 乙 is the Peer. Fire (丙 丁) is what 木 produces, so it is the Output: energy that leaves as work, expression or craft. Earth (戊 己) is what 木 controls, so it is the Wealth. Metal (庚 辛) is what controls 木, so it is the Officer — the element that acts on 甲 and therefore carries the chart's pressure.
Five relations doubled by polarity gives the ten gods, and that is the whole structure. What it does not give you is a verdict on whether 甲 has enough support, because that judgement depends on how much you weight the month of birth, whether hidden stems count fully, and whether rootedness outranks raw count — and three competent practitioners can disagree. So we print the counts and the support/drain split, and leave the weighing to the reading rather than hiding a weighting model inside a score.
Where 甲 turns up in the branches
甲 turns up inside two branches: 寅, where it is the primary hidden stem, and 亥, where it is the middle one. So a chart whose visible characters never mention yang wood can still be carrying it underneath — which is why hidden stems are read rather than ignored.
This matters more than it sounds. Four of the eight characters in a chart are branches, and each branch conceals between one and three stems, so a chart can hold 木 energy in a form that never appears on the surface. The list below is generated from the same fixed hidden-stem table the calculator uses — you can check it branch by branch.
The common misreading
The usual mistake is to read "tree" as "solid and dependable". The image is about direction, not stability: 甲 describes a chart that wants to move along the line it has chosen. Two 甲 day masters may be patient or impatient, generous or austere — that comes from the other seven characters, not from the stem.
A worked example
Every page on this site that needs a worked example uses the same approach: a real birth moment, run through the engine at build time, with the numbers printed so you can reproduce them. This page's example is 8 February 1990, Taipei.
Input
- Date
- 8 February 1990
- Time
- 10:00
- Place
- Taipei, Taiwan
- Time zone
- Asia/Taipei
Nearest 节
Next: 雨水1990-02-19 · 06:14
Year pillar 庚午 — this date is after 立春, which is what sets it.
Day master of this chart
甲 — Yang Wood
Day pillar 甲辰 · 纳音 覆灯火 · image the tall tree
All four pillars, computed at build timeyear · month · day · hour
Year 年
庚午
路旁土
Month 月
戊寅
城头土
Day 日
甲辰
覆灯火
Hour 时
己巳
大林木
- Woodself225%
- Fire225%
- Earth338%
- Metal113%
- Waterabsent
Surface tally 8 of 8 — and no Water at all. Support 2, drain 6, counted across the four stems and four branches and not weighted by season. A single absent element is a fact about this one chart, not a verdict on it.
Ten consecutive days, ten day masters
8 February 1990 gives 庚午 戊寅 甲辰 己巳 — the day pillar is 甲辰, so the day master is 甲. It belongs to a run of ten consecutive dates, 30 January to 8 February 1990, which produce all ten day masters exactly once, because the day pillar advances one step per calendar day and ten steps cycle through all ten stems. That same run straddles the exact minute 立春 fell in 1990 (4 February, 10:14 local), so the earlier dates sit in the 己巳 year and the later ones in the 庚午 year — which also flips the luck-pillar direction, since direction follows the year stem's polarity. On this chart the surface tally is Wood 2 · Fire 2 · Earth 3 · Metal 1 · Water 0 — support 2, drain 6, and the luck pillars run forward from 己卯.
Engine v1.1.0 · lunar-javascript@1.7.7 · these four pillars and this tally reproduce exactly from the input above, in your browser or ours.
The full stem map, computed
These ten names are not a list to memorise — they are computed by one rule: the element relation between the two stems, multiplied by whether their polarities match. The table is produced by the engine from that rule, and it changes completely the moment the day master changes away from 甲.
Peer
Same element as the day master
- 甲比肩 · Companion
- 乙劫财 · Rob Wealth
Output
What the day master produces
- 丙食神 · Eating God
- 丁伤官 · Hurting Officer
Wealth
What the day master controls
- 戊偏财 · Indirect Wealth
- 己正财 · Direct Wealth
Officer
What controls the day master
- 庚七杀 · Seven Killings
- 辛正官 · Direct Officer
Resource
What produces the day master
- 壬偏印 · Indirect Seal
- 癸正印 · Direct Seal
甲 against itself is a Peer of the same polarity, so it is always Companion 比肩. The other nine stems divide across the five relations with two in each — which is why there are exactly ten names and never eleven.
The hidden-stem table, filtered to 甲
A stem does not have to appear on the surface of a chart to be present — every branch carries one to three hidden stems, and this is where the engine finds them. The list below is generated from the same fixed table the calculator uses.
- 寅Tiger · Yín木 · early springprimary hidden stem
- 亥Pig · Hài水 · early wintersecondary hidden stem
寅 carry it as the primary hidden stem; 亥 carry it as a lesser one. A lesser position is not a weaker claim on the element — position matters for weighting, and weighting is the step where published schools disagree.
The other nine day masters
Each stem has its own page, and they are read against each other rather than in isolation — 甲 against 乙, 丙 against 丁. Whichever one is yours, the comparison is usually where the meaning is.
Questions
- What does a Yang Wood day master mean?
- 甲 is wood at the yang pole: the trunk rather than the vine. In practice it means the chart is read for direction and structure first — where does this growth point, and what is it planted in. It is a starting material for a reading, not a character description of a person.
- Is 甲 strong because it is yang?
- No. Yang and yin are a polarity, not a strength scale. 甲 and 乙 are both wood and neither is inherently stronger; whether a chart is "strong" in the classical sense depends on the month of birth, the roots in the branches and the support the whole chart supplies — a judgement we print the inputs for rather than a score.
- How do I know whether my day master is 甲?
- Look at the heavenly stem of your day pillar — the third pillar. In 甲辰 the day master is 甲. The day pillar advances one step per calendar day with no gaps, so your birth date alone is enough to determine it; the birth time is not needed.
- Does a 甲 day master need water?
- Water generates wood, so in the classical cycle water is what feeds 甲 — but "needs" is the wrong question to answer mechanically. Whether a chart wants more water depends on the season, the roots and the relative weight of everything else. That is the useful-god question, and it is exactly where published schools disagree, so we do not print an answer.
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BaziPattern provides AI-generated readings for entertainment and cultural exploration purposes only. Readings are not predictions, or medical, legal, or financial advice.