BaZi day master · 10 of 10

Yin Water Day Master (癸水) in BaZi

癸 is yin water — rain, mist, dew, groundwater. It is read as subtlety and persistence through softness: it does not move things by force, it gets into them. If your day pillar begins with 癸, this is the character every other part of your chart is described relative to.

The short version

癸 is water that works by penetration rather than by volume.

The ten stems’ smallest image carries the system’s largest claim: that arriving quietly is a mechanism, not an absence of one.

Is your day master 癸?

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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.

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How it’s calculated

  1. 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. 2

    Read its heavenly stem

    The stem of that pair is the day master. 癸 is the 10th of the ten stems, so “is my day master 癸?” reduces to one question about one character — and it can be answered from the date alone.

  3. 3

    Set it as the reference

    Once 癸 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 癸 — 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 癸 means as a day master

癸 is water at yin: rain, mist, dew, the water table. Classical practice reads it through penetration — it is the only stem whose image reaches everything without displacing anything. Rain does not push a landscape around; it gets into it, and then things grow on their own schedule.

壬 is its counterpart, and the difference is not quantity. 壬 is read as volume and movement; 癸 is read as subtlety and reach. Neither is described as stronger, and the tradition is explicit that water is the element most dependent on timing — a 癸 chart born in winter and one born in summer are read as entirely different propositions.

The ten gods, read from 癸

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 癸 as the reference the five relations resolve as follows: 水 itself is the Peer, Metal generates 水 and is the Resource, Wood is what 水 produces and is the Output, Fire is what 水 controls and is the Wealth, and Earth is what controls 水 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, 癸 is the day stem itself, so the four visible stems around it each carry one of these names.

What feeds 癸, and what spends it

A chart is not read by counting elements — it is read by what each element does to the day master. Metal (庚 辛) generates 水, so it is the Resource: what supplies 癸 without being asked. 壬 癸 is the Peer. Wood (甲 乙) is what 水 produces, so it is the Output: energy that leaves as work, expression or craft. Fire (丙 丁) is what 水 controls, so it is the Wealth. Earth (戊 己) is what controls 水, so it is the Officer — the element that acts on 癸 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 癸 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 癸 turns up in the branches

癸 appears inside three branches: 子, where it is the primary hidden stem, and 丑 and 辰, where it is a secondary one. Those two are the transitional earth branches of winter and spring, which is why a trace of water is classically said to survive inside them.

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 水 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

癸 is routinely read as the weakest of the ten stems, and that reading does the most damage of any in this list. The image is not smallness — it is a different mechanism. Rain is not a weak river; it is water that does not need to be a river in order to reach the roots of everything in the field.

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 7 February 1990, Taipei.

Input

Date
7 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.

癸Guǐ

Day master of this chart

癸 — Yin Water

Day pillar 癸卯 · 纳音 金箔金 · image the rain

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

    癸卯

    金箔金

  • Hour 时

    丁巳

    沙中土

  • Wood225%
  • Fire338%
  • Earth113%
  • Metal113%
  • Waterself113%
Supports the day master 2Draws on it 6

Surface tally 8 of 8 — all five elements appear at least once. 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

7 February 1990 gives 庚午 戊寅 癸卯 丁巳 — the day pillar is 癸卯, so the day master is 癸. 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 3 · Earth 1 · Metal 1 · Water 1 — 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 癸.

Peer

Same element as the day master

  • 壬劫财 · Rob Wealth
  • 癸比肩 · Companion

Output

What the day master produces

  • 甲伤官 · Hurting Officer
  • 乙食神 · Eating God

Wealth

What the day master controls

  • 丙正财 · Direct Wealth
  • 丁偏财 · Indirect Wealth

Officer

What controls the day master

  • 戊正官 · Direct Officer
  • 己七杀 · Seven Killings

Resource

What produces the day master

  • 庚正印 · Direct Seal
  • 辛偏印 · Indirect Seal

癸 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 癸

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.

  • 子Rat · Zǐprimary hidden stem
  • 丑Ox · Chǒusecondary hidden stem
  • 辰Dragon · Chénsecondary hidden stem

子 carry it as the primary hidden stem; 丑 辰 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 Yin Water day master mean?
癸 is water at the yin pole: rain, mist and groundwater, read as subtlety, persistence and reach. It describes the starting material of a chart, not a temperament — the reading depends on the month of birth and on the other seven characters.
Is 癸 the weakest day master?
No, and the framing is the problem. Polarity is orientation, not quantity, and strength in classical BaZi is a judgement about the whole chart — the month of birth, the roots in the branches and the balance of support and drain. Ranking the ten stems by strength is not something the tradition actually does.
Why is 癸 described as "getting into everything"?
Because the classical image is rain and dew rather than a river: water that reaches a surface without moving it. Read as a chart, that means influence that works by contact and accumulation, and it is why 癸 is usually discussed alongside what it nourishes rather than alongside what it can displace.
What generates 癸, and what does 癸 generate?
Metal generates water, so 庚 and 辛 are Resource relative to 癸. Water generates wood, so 甲 and 乙 are Output — Hurting Officer and Eating God respectively, since 甲 is opposite in polarity to 癸 and 乙 is the same. Every one of those relations is computed for your own chart on the ten gods page.

Full chart

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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.