Yi Hai · 乙亥
Yi Hai pairs 乙, a Yin Wood Day Master, with 亥 (the Pig), a Water branch. Read the upper character first, then the branch and the stems it contains.
The Day Master on top
Yin Wood · 乙 — Yi (乙) is the yin form of Wood. Vines, grasses, and flowers are common images: growth that changes shape as it meets its surroundings. Traditional writing uses this to discuss flexibility and connection.
Learn this Day Master's image and relationships →The branch and its hidden stems
亥 (the Pig) contains 壬, 甲 in the traditional hidden-stem table. Each stem receives a ten-god label by comparing its element and polarity with 乙. The day branch is also traditionally called the spouse palace; that name does not identify a partner's character.
壬
Direct Resource
Yang Water · 壬 → 乙
甲
Rival Wealth
Yang Wood · 甲 → 乙
Na Yin
Yi Hai has the Na Yin label 山头火, "Mountaintop Fire". Thirty names are shared by the sixty pairs. This is a separate classification from the Day Master's element.
Stage of the cycle
Dormant · This is the traditional twelve-stage label for the day stem 乙 in branch 亥. Read it as a stem–branch classification, not a person's age or state of health.
The two unpaired branches (Xun Kong)
乙亥 belongs to the ten-pair group beginning with 甲戌. Its ten stems pair with ten of the twelve branches, leaving 申酉 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 Yi Hai 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.