BAZI KNOWLEDGE BASE
Void in BaZi: six xun table, derivation and a Jia-Chen example
Void (Kong Wang, 空亡) begins with a cyclical relationship: each ten-day xun pairs ten stems with ten branches, leaving two of the twelve branches unmatched within that xun. Those branches are called Void. They are not deleted from a chart when they actually occur.
Which two branches are Void in each xun?
The sixty day pairs form six ten-day xun, each beginning with Jia. Locate the Day Pillar’s range, then read the Void pair. The xun name is its starting day; Void is not restricted to the six Jia days.
| Xun starts | Xun ends | Void branches |
|---|---|---|
| Jia-Zi 甲子 | Gui-You 癸酉 | Xu / Hai |
| Jia-Xu 甲戌 | Gui-Wei 癸未 | Shen / You |
| Jia-Shen 甲申 | Gui-Si 癸巳 | Wu 午 / Wei |
| Jia-Wu 甲午 | Gui-Mao 癸卯 | Chen / Si |
| Jia-Chen 甲辰 | Gui-Chou 癸丑 | Yin / Mao |
| Jia-Yin 甲寅 | Gui-Hai 癸亥 | Zi / Chou |
Why are Yin and Mao Void in the Jia-Chen xun?
Pair the sequence: Jia-Chen, Yi-Si, Bing-Wu, Ding-Wei, Wu-Shen, Ji-You, Geng-Xu, Xin-Hai, Ren-Zi and Gui-Chou. All ten stems have been used, but Yin and Mao have not appeared within the xun.
Bing-Wu therefore belongs to the same Jia-Chen xun and shares its Yin/Mao Void pair. This is neither an opposition lookup from Wu nor a result determined by Bing alone.
Does a Jia-Chen day with Year Yin lose its Year Pillar?
No. With Jia-Chen at the day and Yin at the year, Yin belongs to that day’s Void pair but the Year Pillar (the two-symbol column for the birth year) remains present. Yin still hides Jia, Bing and Wu. Do not remove its elements, roots or contacts and treat the reduced chart as the original.
The Day Branch (the lower symbol in the birth-day column) is necessarily present in its own xun, so it cannot be one of that xun’s missing branches. Clarify checks known pillar branches internally; a Void location can only occur elsewhere. This internal marker is excluded from user-facing interpretation content.
How does interpretation differ from the cycle fact?
Historical texts add discussions of fill-in, contacts, True Void and exchanged Void, each with further conditions. Deriving the two branches does not establish all those variants or predict a missing job or relationship.
First reproduce the six-xun calculation, then separate actual natal symbols from the chosen interpretation. Roots and timing effects can be explored in their own guides after that distinction is clear.