Geng Metal (庚) Day Master: Rock, Iron and Resolve

Geng (庚) is yang Metal, pictured as hard rock and raw iron. This page shows how the tradition describes a chart with 庚 as its day master, how 庚 meets each of the other stems, and which months, foods and habits it reads as a good fit.

Geng at a glance

庚 is the seventh heavenly stem (index 6) and opens the Metal pair; 辛 is its yin partner. The haru engine's image for it is "hard rock and iron": metal still in the ore or freshly cast, strong but not yet shaped. The autumn feel of Metal, when harvests are cut and things are sorted, belongs to it too.

As always, the day master is one of eight characters. The tradition reads the chart from 庚's seat, but the other seven decide how that iron is actually used, so the descriptions below are tendencies of an image.

How the tradition describes the temperament

The stored description is "decisive, pushing straight ahead". Ore does not bend easily and a blade cuts in one line, so commentators describe 庚 with words like resolve and directness. Strengths usually listed:

• Clear decisions, made without long hesitation
• A sense of fairness and of keeping one's word
• Staying power under pressure, like metal that holds its shape
• Willingness to take on hard, practical tasks

Things to watch, gently

Iron that is never tempered can be brittle. The tradition suggests that 庚 may speak more sharply than it intends, or push on when a pause would serve better. Listening a moment longer, and letting others finish before deciding, are habits the image recommends. Both come from the same honesty that makes 庚 easy to trust.

How Geng meets the other nine stems

From 庚's seat, Earth (戊, 己) is the resource that produces Metal, Water (壬, 癸) is what Metal produces, Wood (甲, 乙) is its wealth and Fire (丙, 丁) is the officer pair. The yang Fire stem 丙 is 庚's Seven Killings, while the yin candle 丁 is its Direct Officer, which fits the old picture of a small, steady flame working iron into a tool.

Which months help Geng

By the deLing rule in saju2.js, a month helps when its branch element is Metal or Earth. That gives six branches: 申 and 酉 (Metal) and 丑, 辰, 未, 戌 (Earth). In the 2026 cycle the Metal months opened at 立秋 on 2026-08-07 and 白露 on 2026-09-07 (KST).

A helping month adds 8 to the support score and any other month subtracts 8; 55 or more reads as strong, 40 or less as weak. Two rows are worth a look. The 巳 month is Fire and does not count as helping, yet it hides 庚 itself for 7 days next to 戊 for 7. The 申 month carries 庚 for 16 days, the longest stretch of the day master's own stem in any branch.

Foods, and the reasoning behind them

haru chooses foods from the useful element. For a weak 庚 chart that is Earth or Metal, whichever is scarcer (the weak_help rule). For a balanced or strong chart, saju2.js sorts Water, Wood and Fire by their share and takes the smallest (strong_release or balance_least). A summer birth with Water under 15% and Fire at 25% or more goes straight to Water.

Classical texts often say 庚 is refined by 丁 fire and shows its edge when washed by water. That is why the Fire and Water rows matter so often for this stem: red, bitter foods such as tomato and jujube, or black, salty ones such as kelp and black beans, taken as ordinary meals.

Movement and rest

Rest windows and movement ideas follow the same useful element. The three most common for 庚:

• Earth (resource): barefoot walking, yoga; rest window 未時 13~15 h, close the eyes briefly after lunch.
• Metal (own element): deep breathing, light strength training; rest window 酉時 17~19 h, a quiet pause to breathe at dusk.
• Water (output): swimming, waterside walks, slow stretching; rest window 亥時 21~23 h, go to bed early.

Questions

Is a Geng day master always strong-willed?

The tradition describes the image that way, but it reads the whole chart. A 庚 born in a Wood month with little Earth may read as weak, and the engine would then point to Earth or Metal for support.

Which month branches help 庚?

Metal and Earth branches: 申, 酉, 丑, 辰, 未 and 戌. The other six, 寅 卯 (Wood), 巳 午 (Fire) and 亥 子 (Water), do not.

Why are 丙 and 丁 different ten gods for 庚?

Both are Fire, which controls Metal. 丙 is yang like 庚, so it is the Seven Killings; 丁 is yin, so it is the Direct Officer.

Where can I see my own day master?

The day master page computes the day pillar from a birth date and time; its top character is the day master.

Read next

Traditional Four Pillars (myeongni) and yin-yang five-element interpretation. Not a medical diagnosis or advice.