庚 Geng
Yang Metal, raw metal, the axe, the unrefined ore. Direct, decisive, and comfortable with the cut that other people are avoiding.
What a Geng day master is
Yang Metal is unfinished and strong. It is the blade before polishing: useful, blunt, and honest to a fault. Geng people say the thing, make the call, and end what needs ending. They are the ones you want when a decision has been deferred too long.
In Chinese astrology your core element is Yang Metal, pictured as raw ore and the axe. You are decisive and built for hard calls, and pressure only sharpens you.
Geng at its best, and where it strains
Strength. Decisiveness and a genuine tolerance for necessary conflict.
Difficulty. Raw metal cuts what it did not intend to. Geng can wound people while being accurate, and can mistake bluntness for integrity.
Geng shares its element with Xin, the yin form of Metal, and the two behave nothing alike. That is the whole reason BaZi uses ten stems rather than five.
The four relationships every BaZi reading runs on
Your day master is not read alone. Everything else in the chart is judged by how it treats Metal, and the five elements move in two cycles: one that nourishes and one that restrains. For a Metal day master those come out as follows.
A chart with plenty of Earth and little Fire reads very differently from the reverse, even with the same day master. That balance is what a BaZi practitioner is actually looking at, and it is why two Geng people can be unrecognisable to each other.
BaZi pillars here use the solar calendar the tradition uses, so the year turns at Lichun in early February rather than at the lunar new year, and the hour pillar follows the late-Zi convention.