Stems, Branches, Ganzhi
Last updated 5/21/2026
Pick up Case 1 again. The readable cast header is:
Void branches for this ten-day cycle: Yin and Mao.
Act 2 taught us the cast diagram under that header. Act 3 starts by reading the header itself.
The header names the time of the cast. In Wen Wang Gua, that time is not background information. It tells us which lines are strong, weak, void, broken, supported, clashed, or secretly active.
The two lists
The traditional calendar uses two ordered lists:
Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui.
Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai.
Together, a stem plus a branch make a ganzhi pair. A day such as Wu-Shen means: Wu stem plus Shen branch.
The reference layer keeps technical source labels for each stem and branch. The lesson flow uses romanized working labels so the calendar can be learned as a system instead of as a wall of symbols.
Reference links: Ganzhi, Wu stem, Shen branch, Five Phases.
Source basis: Bushi Zhengzong, Five Phases attributes table; Zengshan Buyi case headers. The working labels here follow the course terminology reference.
The ten stems
Each stem has a polarity and an element. The elements move in pairs:
Jia is yang Wood. Yi is yin Wood.
Bing is yang Fire. Ding is yin Fire.
Wu is yang Earth. Ji is yin Earth.
Geng is yang Metal. Xin is yin Metal.
Ren is yang Water. Gui is yin Water.
The important thing is not the source character. The important thing is the element and polarity carried by the stem.
The twelve branches
Branches also have elements and polarity, but they do not divide into five neat two-branch pairs. Earth appears four times because it marks seasonal transitions.
Winter branches. Zi is yang; Hai is yin.
Spring branches. Yin is yang; Mao is yin.
Summer branches. Si is yin; Wu is yang.
Autumn branches. Shen is yang; You is yin.
Transition branches. Chou and Wei are yin; Chen and Xu are yang.
The zodiac animal names are cultural memory aids, not reading mechanics. In this course, Shen matters because it is a Metal branch, not because of its animal association.
How the 60-cycle works
The stems and branches advance together.
Start with stem 1 and branch 1. Then advance both lists by one step. When the ten stems run out, the stems wrap back to the beginning while the branches keep going. When the twelve branches run out, the branches wrap too.
Because one list has ten items and the other has twelve, the pairings return to the start after 60 steps.
Stem 1 + branch 1.
Both lists move one step.
The same advance continues.
The stem list reaches its end.
Stems restart; branches keep going.
The full cycle closes.
Stem moves one position. Branch moves one position.
The stem list wraps after ten. The branch list wraps after twelve.
The full cycle completes when both lists return to their first position together.
This is why the system has 60 valid day names, not 120. Yang stems pair only with yang branches. Yin stems pair only with yin branches. If a source gives you a yang stem with a yin branch, it is not a real calendar pair.
What the cast header needs
A full traditional date can include year, month, day, and hour. Wen Wang Gua usually emphasizes two of those:
- Month branch: the strongest baseline influence on every line.
- Day pair: the immediate trigger, including the day branch and the day stem.
The year and hour can matter in specialized cases, but they are not the main Act 3 engine. Most classical case headers give the month and day because those are the two calendar positions that do the heavy work.
This convention is not a shortcut. It is the hierarchy of the method. The Month branch sets the strength environment. The Day pair supplies the immediate trigger, with the day stem also rotating the Six Spirits from Act 2. Year and hour stay in peripheral vision until a domain or timing question specifically asks for them.
Case 1
Case 1 uses:
Earth. This will make Earth lines seasonally important and will break the opposite Earth branch, Xu.
Wu is an Earth stem. Shen is a Metal branch. The Shen branch does the main interaction work in this case.
These two branches are temporarily unfunded in this ten-day cycle. The next module explains why.
This is already enough to see why two casts with the same hexagram can read differently. Change the month or day, and every line is measured against a different calendar condition.
What to remember
The stem or branch name matters because it carries an element and a yin/yang quality.
The cast header's month branch and day pair are the main calendar anchors for Act 3.
Zodiac animal labels can help memory, but they do not drive the Wen Wang Gua calculation.
The beginner trap
Do not memorize the 60-cycle as a long list.
Learn the interleaving rule. If you know the stem order, the branch order, and the rule that both lists advance together, you can regenerate the cycle when you need it. The full 60-list is the output of the rule, not the thing to carry in your head.
Where this lands us
We now know what a cast date is made of: stems, branches, and 60 repeating stem-branch pairs.
Next we look inside that 60-cycle. It is not one undivided loop. It is six ten-day cycles, and each ten-day cycle leaves two branches temporarily void. That is why Case 1 has the void pair Yin / Mao in its header.
→ 3.2 The Ten-Day Xun and Void.