Jia Zi 甲子 Day Pillar
Jia Zi 甲子 is number 1 of the sixty. The Day Master is Jia 甲, yang Wood; the branch Zi 子 is Water, zodiac Rat. Na Yin is Gold in the Sea.
At a glance
| Position in the cycle | 1 / 60 |
|---|---|
| Day Master (stem) | 甲 |
| Day branch | 子 |
| Day Master element | yangWood |
| Branch element | Water |
| Zodiac | Rat |
| Na Yin | Gold in the Sea |
| Hidden stems | Gui 癸 |
| Void branches | Xu 戌, Hai 亥 |
Hidden stems and their Ten Gods
A branch is more than its surface element. Zi 子 hides Gui 癸; read against the Day Master Jia 甲 they give the Ten God relations below. Hidden stems are what element strength is actually judged on — counting only the four visible stems badly understates what the branches carry.
| Hidden stems | Day Master element | Ten God |
|---|---|---|
| Gui 癸 | Water | Direct Resource |
Next Jia Zi 甲子 days
Day pillars run on a fixed 60-day cycle independent of month and year. The dates below are derived straight from the day count, so no calendar reform affects them.
- Calculating…
Where Jia Zi 甲子 sits in a chart
The day pillar is the only one read from itself — every Ten God in the year, month and hour pillars is defined relative to the Day Master Jia 甲. Two people born in the same year and month with different day stems therefore have completely different charts. In Jia Zi 甲子 the Day Master Jia 甲 is yang Wood and sits on Zi 子, which is Water; the relation between them is branch produces the Day Master. This seat is classically read as the Day Master's immediate environment.
Related pillars
The other five pillars sharing the Day Master Jia 甲, and the other four sharing the branch Zi 子:
Same Day Master (Jia 甲)
Same branch (Zi 子)
Sources
- lunar-javascript (6tail, MIT) — solar-term instants, 干支 pillars, 大運/流年, 胎元/命宮/身宮 and the almanac tables.
- Hong Kong Observatory, Date and Time of the 24 Solar Terms — the reference used to check solar-term instants.
- Xieji Bianfang Shu and Sanming Tonghui — classical sources for the Wuhu Dun and Wushu Dun stem rules, hidden stems and the Ten Gods.
Algorithms last checked: 2026-07 · Method and accuracy