Ji Si · 己巳
Ji Si pairs 己, a Yin Earth Day Master, with 巳 (the Snake), a Fire branch. Read the upper character first, then the branch and the stems it contains.
The Day Master on top
Yin Earth · 己 — Ji (己) is Yin Earth. Cultivated soil is its common image: a place where seeds, water, and time can meet. The metaphor explains associations with receiving and tending.
Learn this Day Master's image and relationships →The branch and its hidden stems
巳 (the Snake) contains 丙, 庚, 戊 in the traditional hidden-stem table. Each stem receives a ten-god label by comparing its element and polarity with 己. The day branch is also traditionally called the spouse palace; that name does not identify a partner's character.
丙
Direct Resource
Yang Fire · 丙 → 己
庚
Output (Sharp)
Yang Metal · 庚 → 己
戊
Rival Wealth
Yang Earth · 戊 → 己
Na Yin
Ji Si has the Na Yin label 大林木, "Great Forest Wood". Thirty names are shared by the sixty pairs. This is a separate classification from the Day Master's element.
Stage of the cycle
Peak · This is the traditional twelve-stage label for the day stem 己 in branch 巳. Read it as a stem–branch classification, not a person's age or state of health.
The two unpaired branches (Xun Kong)
己巳 belongs to the ten-pair group beginning with 甲子. Its ten stems pair with ten of the twelve branches, leaving 戌亥 outside that group. Those two are called Xun Kong, or "void branches".
Keep the Day Master, change the branch
These day pillars share the same upper character. Compare their hidden stems to see why a Day Master alone cannot describe all the chart relationships.
Is Ji Si actually your day pillar?
Calculate all four pillars from your birth details, then check the day column. Near the day boundary, birth time and the calculator's time conventions can affect the result.
This reference describes one of four pillars. The calculator shows the full chart and the birth details used to produce it.