The 18 Dun Periods (遁局) of Qi Men Dun Jia — the temporal axis of the system. The year divides into 陽遁 (Yang Dun, the expansive forward-rotating half-year from Winter Solstice through to Mid-Summer) and 陰遁 (Yin Dun, the receding backward-rotating half-year from Summer Solstice through to Mid-Winter). Each half subdivides into 9 numbered dun periods that anchor at specific palaces during specific solar-term ranges.
The 18 Dun Periods: temporal axis of QMDJ
This is the master reference for the 18 Dun Periods (遁局) of Qi Men Dun Jia. Each dun period is a temporal slot during which the chart's energetic configuration follows a specific anchoring and rotation pattern. The dun period is the foundational temporal layer of any consultation — the "canvas" on which the gate / star / spirit / stem distribution is drawn.
Voice constraint: these pages name each dun period and identify its solar-term coverage and general register. They do not teach the chart-casting procedure that determines exactly which dun is operating at a given time, nor the rotation logic that distributes components across palaces. For chart-aware reading of a specific consultation, book a QMDJ forecasting service; for learning the chart-casting methodology, the QMDJ Bootcamp covers this in detail.
Yang Dun 陽遁 (1–9) — the expansive half-year
Operates roughly Winter Solstice through Mid-Summer. Forward (clockwise) rotation. Energy is expansive and outward-moving.
Operates roughly Summer Solstice through Mid-Winter. Backward (counterclockwise) rotation. Energy is receding and inward-consolidating. Listed in descending number order to match the solar-term progression.
How dun periods integrate with the rest of the chart
The dun period is the temporal foundation — it determines where the leader stem starts and which direction the components rotate.
The 9 stars rotate across the chart with the dun period — different duns produce different star distributions across the 9 palaces.
The 8 gates similarly rotate — different duns place different gates at different palaces.
The 8 spirits rotate — different duns produce different spirit distributions.
The 9 stems (三奇六儀) distribute across the palaces based on the dun period.
Reading the chart for a consultation involves identifying which palace is relevant to the question, then reading the gate / star / spirit / stem combination at that palace against the question's specific context.
Steps 1–5 are the chart-casting procedure that the QMDJ Bootcamp covers; this reference library covers what each component means at each palace, but not how to determine where each component lands.
Frequently asked questions
What is a Qi Men Dun Jia dun period?
A dun period (遁局) is a temporal energetic configuration that operates during specific solar-term ranges. The 18 dun periods divide the year into yang dun (forward-rotating, expansive) and yin dun (backward-rotating, receding) halves, each with 9 numbered sub-periods. The dun period anchors the chart at a specific palace and determines the rotation direction of all subsequent components.
How do I know which dun period is currently operating?
The dun period is determined by the date and time of consultation, mapped against the 24 solar terms and their thirds (upper / middle / lower). The chart-casting procedure that determines the exact dun is the work of a chart-aware practitioner — covered in the QMDJ Bootcamp curriculum for self-study, or built into the forecasting consultation when you book one.
Why are there only 18 dun periods if there are 24 solar terms?
The 24 solar terms each subdivide into upper / middle / lower thirds, and the dun-period rotation cycles through 1–9 across these thirds. The result is that 9 yang dun + 9 yin dun = 18 distinct configurations, each operating during multiple solar-term thirds across the year. The dun-period system thus has finer temporal resolution than the 24 solar terms alone.
Does the dun period change during a single consultation?
Within a single consultation (typically lasting one or a few hours), the dun period stays constant — the chart cast for that consultation is the relevant chart for the entire consultation. New consultations cast at different times during the same day may fall within the same or different dun periods depending on solar-term boundaries.
QI MEN DUN JIA FORECASTING
Get a chart-aware QMDJ reading for your specific question.
Master Sean Chan’s Qi Men Dun Jia forecasting consultation reads the specific question you bring against the current dun period’s chart. The reading identifies which gates / stars / spirits are activating for your question, what classical patterns are present, and the favourable timing window for your action. Zero generic advice — every consultation is chart-specific.
Master Sean Chan’s free Qi Men Dun Jia calculator plots the current chart for any time of day. Use it to see the current dun period’s gate / star / spirit / stem distribution across the nine palaces — useful for self-study, but no substitute for chart-aware reading of a specific question.
Master Sean Chan’s QMDJ Bootcamp takes you from beginner through intermediate — chart casting from date and time, the dun-period mechanism, the heaven/earth board rotation, and how to read the 9 stars / 8 gates / 8 spirits / 9 palaces / 9 stems for actual consultation questions. The bootcamp teaches the methodology these reference pages deliberately omit, so you can read charts for yourself.