The Four Schools of Qi Men Charting: Chai Bu (拆補), Zhi Run (置閏), Mao Shan (茅山) & Yin Pan Daojia (陰盤)
undefined
⚡ Executive Summary & Key Takeaways
- Why 4 Schools Exist: One solar term averages 15.2184 days, whereas Three Yuan of 60 hours each equal exactly 15.0000 days, creating an annual surplus of 5.2422 days across 24 solar terms.
- Chai Bu Method (拆補法): Switches the solar term at the exact minute the Sun crosses its ecliptic longitude, then looks backward from the current Day Jiazi to the nearest Jia or Ji Lead Stem (Fu Tou 符頭) to determine Upper, Middle, or Lower Yuan.
- Fu Tou Branch Law: Earthly Branches Zi, Wu, Mao, You govern the Upper Yuan; Yin, Shen, Si, Hai govern the Middle Yuan; Chen, Xu, Chou, Wei govern the Lower Yuan.
- Yin Pan Daojia (陰盤奇門): Ignores solar terms entirely, computing the chart number via $(YearBranch + LunarMonth + LunarDay + HourBranch) pmod 9$, using Winter/Summer Solstice only to separate Yang Dun from Yin Dun.
1. The Astronomical Root of the Four Charting Schools
Why do two Qi Men Dun Jia software programs or classical masters sometimes produce different chart numbers for the exact same date and hour? The answer lies in astronomical mathematics. In the Sexagenary cycle, one Yuan equals 60 double-hours (5 days), and Three Yuan equal 15 days. Across 24 Solar Terms, $24 imes 15 = 360$ days. However, Earth's true tropical orbit around the Sun takes 365.2422 days. Every solar term averages 15.2184 days, leaving an extra 5 hours and 14 minutes per solar term and 5.2422 extra days per year.
To reconcile this 5.24-day annual gap between astronomical solar longitude and the 60-Jiazi cycle, historical lineages developed four distinct solutions: Chai Bu (Split-Supplement), Zhi Run (Intercalation), Mao Shan Daoist, and Yin Pan Daojia.
2. The Fu Tou (符頭) Algorithm & Three-Yuan Branch Law
In both the Chai Bu and Zhi Run systems, the Yuan (Upper, Middle, or Lower) of any given day is determined by tracing backward from the current Day Pillar along the 60-Jiazi table until reaching the nearest stem Jia (甲) or Ji (己). That Jia or Ji pillar is called the Day Fu Tou (Lead Stem), and its Earthly Branch dictates the Yuan:
子午卯酉為上元，寅申巳亥為中元，辰戌丑未為下元。 Zi Wu Mao You wei Shang Yuan, Yin Shen Si Hai wei Zhong Yuan, Chen Xu Chou Wei wei Xia Yuan.“When the Fu Tou Branch is Zi, Wu, Mao, or You, it is Upper Yuan; when Yin, Shen, Si, or Hai, it is Middle Yuan; when Chen, Xu, Chou, or Wei, it is Lower Yuan.”
Yanbo Diaotu Ge & Yuding Qimen Baojian
Zi · Wu · Mao · You
Day Fu Tou pillars: Jia Zi, Jia Wu, Ji Mao, Ji You. Selects the 1st chart number of the current Solar Term.
Yin · Shen · Si · Hai
Day Fu Tou pillars: Jia Yin, Jia Shen, Ji Si, Ji Hai. Selects the 2nd chart number of the current Solar Term.
Chen · Xu · Chou · Wei
Day Fu Tou pillars: Jia Chen, Jia Xu, Ji Chou, Ji Wei. Selects the 3rd chart number of the current Solar Term.
3. Deep Comparison of the Four Charting Schools
| Criterion | 1. Chai Bu (拆補法) | 2. Zhi Run (置閏法) | 3. Mao Shan (茅山法) | 4. Yin Pan (陰盤道家) |
|---|---|---|---|---|
| Solar Term Switch | Switches at the exact minute of astronomical Solar Term transition. | Switches on the Jia Zi / Ji Mao Upper-Yuan Fu Tou day (Chao Shen / Jie Qi). | Switches at the exact minute of astronomical Solar Term transition. | Does not use 24 Solar Terms; uses only Solstices for Yang/Yin Dun. |
| Yuan Determination | By Day Pillar's Fu Tou (Jia/Ji) Earthly Branch group. | Unbroken 15-day Three-Yuan blocks; duplicates Mang Zhong or Da Xue when Chao Shen exceeds 9 days. | First 60 hours = Upper Yuan; hours 61 to 120 = Middle Yuan; remaining hours = Lower Yuan. | Formula: $(YearBranch + Month + Day + HourBranch) pmod 9$. |
| Center Palace 5 | Tian Qin resides in Kun 2 (or Gen 8 in Yin Dun). | Tian Qin resides in Kun 2. | Tian Qin resides in Kun 2. | Rotates all 9 Palaces or includes Hidden Stems (An Gan) outside palaces. |
| Primary Domain | Universal standard for horary divination, business, and date selection. | Imperial court archives, macro-cycles, and classical treatise research. | Astronomical field rituals and Daoist talismanic timing. | Spatial Feng Shui diagnosis and Shifting Stars remedies. |
4. Step-by-Step Verification Example
Suppose a practitioner examines a chart on a Xin Si (辛巳) day during the Frost's Descent (Shuang Jiang 霜降) solar term. Tracing backward from Xin Si (Xin Si, Geng Chen, Ji Mao), the nearest Jia or Ji stem is Ji Mao (己卯). Because the branch Mao (卯) belongs to the Zi-Wu-Mao-You group, the day is in the Upper Yuan. Looking up Frost's Descent in Table 1.1 (Yin Dun [5, 8, 2]), the Upper Yuan yields Yin Dun Chart 5. You can verify all four schools side by side in Master Ung Khiem's 4-School Qi Men Plotter.
🧭 Launch Master Ung Khiem's Interactive Qi Men Dun Jia Software
Plot real-time Qi Men Dun Jia charts across all 4 Classical Schools (Chai Bu, Zhi Run, Mao Shan, Yin Pan Daojia) with True Solar Time, Four Afflictions alerts, and 100 Stem Interactions analysis:
Frequently Asked Questions (FAQ)
1. Which charting school is the most accurate for daily strategic divination?
The Chai Bu (Split-Supplement) school is the most widely validated in modern clinical practice because it honors both the exact astronomical moment of solar longitude transition and the classical Jia/Ji Fu Tou structure without artificial 15-day drift.
2. Why does Zhi Run Qi Men only intercalate at Grain in Ear (Mang Zhong) and Major Snow (Da Xue)?
Because Mang Zhong immediatamente precedes the Summer Solstice (where Yang Dun switches to Yin Dun), and Da Xue immediately precedes the Winter Solstice (where Yin Dun switches to Yang Dun). Inserting a duplicate 15-day Three-Yuan cycle right before the Solstice resets the accumulated Chao Shen drift.