How to Cast a Qimen Dunjia Chart, Step by Step
Many people assume casting a chart is the practitioner's judgement. In fact, from the moment in time to the finished chart, every step is a fixed rule. This article walks through them.
Step 1: Fix the dun type — Yang Dun after the winter solstice, Yin Dun after the summer solstice
The year splits in two: from the winter solstice to the next summer solstice is Yang Dun (陽遁); from the summer solstice to the next winter solstice is Yin Dun (陰遁). The dividing line is the exact moment of the solar term, not a lunar month and not Chinese New Year.
Do not underestimate this step. Get the dun type wrong and the direction of every later placement (forward or backward) flips — the whole chart is wasted.
Step 2: From the solar term and the three yuans, find the ju number
Each of the 24 solar terms carries three ju numbers, one for each of the upper, middle and lower yuans (上元／中元／下元). For example: winter solstice 1・7・4, Minor Cold 2・8・5, Major Cold 3・9・6; summer solstice 9・3・6, Minor Heat 8・2・5. Know which term and which yuan you are in, and you know which ju to use.
Which yuan applies is fixed by the fu tou (符頭): the most recent Jia or Ji day on or before the day in question. Look at the earthly branch of that fu-tou day: Zi, Wu, Mao, You → upper yuan; Yin, Shen, Si, Hai → middle yuan; Chou, Chen, Wei, Xu → lower yuan.
Step 3: Lay the earth plate — the Three Marvels and Six Rites
Take Yin Dun 6 as the example: Wu goes into palace 6, then the stems continue in the order Wu, Ji, Geng, Xin, Ren, Gui, Ding, Bing, Yi — backward for Yin Dun (forward for Yang Dun). Once the Three Marvels (三奇) and Six Rites (六儀) fill all nine palaces, the earth plate is done. This layer is the reference for every judgement that follows.
Step 4: Find the xun head and the Chief Star, and rotate the heaven plate
From the hour pillar, find the xun head (旬首) — the sixty jiazi fall into six ten-day cycles, each opening with a Jia stem, and the Jia hides within the Six Rites — then find which palace that stem occupies on the earth plate. The star whose home is that palace becomes the Chief Star (值符星). The other eight stars shift as a block clockwise around the outer ring, following the Chief Star (Tianqin always stays in the central palace 5 and is read via Kun 2). The heaven-plate stems are the stems carried by those stars, laid on top in the same move.
Step 5: Place the eight gates, starting from the Envoy Gate
The gate corresponding to the xun head is the Envoy Gate (值使門). It leads as the gates are placed forward for Yang Dun and backward for Yin Dun; the central palace 5 has no gate, and matters there are read via Kun 2.
Step 6: Place the eight spirits
Start the "Chief" spirit from the palace holding the Chief Star, then place the other seven spirits in their fixed order — forward for Yang Dun, backward for Yin Dun. The eight spirits occupy only eight palaces; the central palace 5 has no spirit.
A worked chart (the same example)
Casting 2026-09-12 22:00 (Hong Kong time) gives: a Ji Chou day, a Yi Hai hour, xun head Jia Xu, Yin Dun 6, Chief Star Tianqin, Envoy Gate Death, Void in Shen and You, Horse at Si. The nine palaces come out as follows:
| Palace | Direction | Heaven-plate star | Gate | Spirit | Heaven-plate stem / Earth-plate stem |
|---|---|---|---|---|---|
| Kan 1 (坎一) | North | Tianxin (天心) | Harm (傷門) | Nine Earth (九地) | Wu / Gui |
| Kun 2 (坤二) | South-west | Tianying (天英) | Open (開門) | Serpent (螣蛇) | Ding / Ren |
| Zhen 3 (震三) | East | Tianren (天任) | Scenery (景門) | White Tiger (白虎) | Bing / Xin |
| Xun 4 (巽四) | South-east | Tianchong (天沖) | Death (死門) | Six Harmony (六合) | Xin / Geng |
| Center 5 (中五) | Center | Tianqin (天禽) | (read via Kun 2) | — | Ji |
| Qian 6 (乾六) | North-west | Tianzhu (天柱) | Life (生門) | Nine Heaven (九天) | Yi / Wu |
| Dui 7 (兌七) | West | Tianrui (天芮) | Rest (休門) | Chief (值符) | Ren / Yi |
| Gen 8 (艮八) | North-east | Tianpeng (天蓬) | Delusion (杜門) | Dark Warrior (玄武) | Gui / Bing |
| Li 9 (離九) | South | Tianfu (天輔) | Fear (驚門) | Great Yin (太陰) | Geng / Ding |
This chart is the result of the six steps above — you can cast a free chart for the same time and check every square against it. The same steps done in the tool are covered in the calculator guide.
The four places where casting goes wrong
- The term-change day. On the day one solar term gives way to the next (White Dew falls around 7 September), picking the wrong term throws off the ju number and the entire earth plate.
- The day-change point. Whether the late Zi hour (after 23:00) belongs to the next day or the current one differs between schools. This site follows the tradition that a new day begins at the Zi hour.
- Time zone. Key in local time as if it were UTC and the hour pillar lands one slot off — everything in that eight-shichen span is then wrong.
- How the solar term and three yuans are taken. The chaibu (拆補, fill-in) and zhirun (置閏, intercalation) methods give different results. When another site does not match this one, this is usually why — not necessarily an error.