Day Pillar #1 · 甲子
| Position in the cycle | #1 of 60 |
|---|---|
| Heavenly stem 天干 | 甲 — 木 Wood |
| Earthly branch 地支 | 子 — 水 Water |
| Nayin 纳音 | 海中金 — Gold in the Sea (Metal) |
| Hidden stems 藏干 | 癸 — 癸 (Water) |
| Twelve-stage placement 十二长生 | 沐浴 — Bathing (of the stem in its own branch) |
Jiazi (甲子) is the first of the sixty day pillars — the head of the cycle, yang wood sitting on the branch of deepest water.
The Ming-dynasty encyclopedia San Ming Tong Hui runs a compact register of all sixty pillars, giving each one an image and a condition. Jiazi gets three characters:
甲子金，为宝物，喜金木旺地。
Jiazi metal: a treasure. It favours ground where metal and wood are flourishing.
The nayin — the "sound element" layer, which assigns a separate element to each pair of pillars and ignores stem-and-branch logic entirely — files 甲子 and 乙丑 together as 海中金, Gold in the Sea. The text explains the name by developmental stage rather than by substance:
甲子乙丑何以取象为海中之金？盖气在包藏，有名无形，犹人之在母腹也。
Why are Jiazi and Yichou taken as gold in the sea? Because the energy is still wrapped and contained — it has a name but no form, like a person still in the womb.
And on what that gold needs in order to surface:
海中金者，宝藏龙宫，珠孕蛟宝，出现虽假于空冲，成器无借乎火力。
Gold in the sea: treasure stored in the dragon's palace, pearls conceived in the depths. It surfaces only by way of a clash into emptiness; it does not rely on fire to become a vessel.
Note the last clause, because it is the useful one. Most metal in this system is made into something by fire — the forge. This metal is the exception: it is already formed, and what it lacks is not heat but exposure. The classical image is a quiet kind of brilliance, complete before anyone sees it.
Sources: 《三命通会》 (San Ming Tong Hui, Ming, 万民英) and 《滴天髓》 (Di Tian Sui) — both quoted from local plain-text editions and verified character by character. Translations are ours. Corrections are welcome.
Enter a birth date and time to get the four pillars, the hidden stems, the nayin and the twelve-stage placements for a real chart — the same tables this page is built on.
Open the chart calculator →乙丑 Yichou · 丙寅 Bingyin · 丁卯 Dingmao · 壬申 Renshen · 癸酉 Guiyou · 甲戌 Jiaxu · all sixty →