Qi Men Dun Jia

What's in the chart

• Nine palaces on the Lo Shu square: the eight directions and the center. Chinese charts put south at the top, and so does this one.
• The Earth Plate: nine characters, the “Three Wonders and Six Instruments,” laid out according to the ju. In the hour chart it stays fixed for five days; in the day, month and year charts, longer.
• The Heaven Plate: the same characters, rotated along with the nine stars to follow the hour (in the day chart, the day, and so on).
• Nine stars, eight doors and eight deities: what is happening in each direction during this hour, day, month or year.
• The Void and the Travelling Horse, from the chart's pillar: two markers practitioners look at first.

Below the chart is a table of meanings and the directions tradition considers favorable for setting out and starting things: those with the Rest, Life or Open door outside the Void.

How the chart is built

• Ju. Each of the 24 solar terms is divided into three five-day “yuan.” The term and the yuan give the ju number from 1 to 9 and the direction: from the winter solstice to the summer solstice it is Yang Dun, after that Yin Dun.
• The Earth Plate. The character 戊 goes into the palace with the ju number, the rest follow in the order 己 庚 辛 壬 癸 丁 丙 乙: forward in Yang Dun and backward in Yin Dun.
• The Duty Star. The hour pillar belongs to one of six decades, and each decade has its own “hidden” character. The star of the palace where that character sits on the Earth Plate becomes the Duty Star and moves to where the hour stem sits on the Earth Plate. The other stars rotate with it.
• The Duty Door of the same palace moves by as many palaces as hours have passed since the start of the decade; the other doors rotate after it.
• The deities are placed starting from the Duty Star: clockwise in Yang Dun and counterclockwise in Yin Dun.

The center star Tian Qin and the center character “live” in the southwest, together with Tian Rui, as is customary in the rotating plate method. We checked Chai Bu charts against the independent qimen-rs implementation on fifteen hundred random moments: the ju, both plates, stars, doors and deities matched every time.

Chai Bu and Zhi Run

The main debate in Qi Men is how to tie the five-day yuan to the solar terms. A yuan starts on a fu tou day with the stem 甲 or 己, while solar terms start at any time, so their boundaries do not coincide.

Chai Bu (“cut and patch”) takes the solar term that is actually in effect and the yuan from the nearest fu tou. This is simple and astronomically accurate, but a yuan sometimes starts in the middle.

Zhi Run (“insert a leap”) ties each upper yuan to a whole solar term. The fu tou gradually gets ahead of the term; when, at Grain in Ear or Major Snow, the lead exceeds nine days, the term is repeated — a fifteen-day “leap” block is inserted.

In about a third of hours the systems give different ju, and the calculator warns you about it. Many teachers advise beginners to choose times when both systems agree for important matters.

Day, Month and Year Charts

Besides the hour chart, the tradition builds charts for the day, month and year. The plate is the same rotating plate, with the same stars, doors and deities, but the day, month or year pillar takes the place of the hour pillar: it determines the decade, the Duty Star, the Duty Door, the Void and the Travelling Horse. Only the ju is chosen differently.

• Year chart. Always Yin Dun. Years are grouped into 60-year yuan, and three yuan make a 180-year cycle: the upper yuan (1864–1923; the next one begins in 2044) is ju 1, the middle (1924–1983) is ju 4, the lower (1984–2043) is ju 7. As in BaZi, the year is counted from Lichun (“Start of Spring,” around February 4). For example, 2004, a 甲申 year, belongs to the lower yuan: Yin Dun, ju 7.
• Month chart. Always Yin Dun. A yuan lasts five years (sixty months) and begins with a year whose stem is 甲 or 己, the fu tou year. The ju is set by that year's branch: 子 午 卯 酉 give ju 1, 寅 申 巳 亥 give ju 4, 辰 戌 丑 未 give ju 7. The year is counted from Lichun, and the months are solar: each runs from one jie solar term to the next. For example, for the 辛未 month of 2004, the yuan began that same year, 2004 (甲申), with the branch 申, so it's Yin Dun, ju 4.
• Day chart. The solar terms divide the year into six blocks of about 60 days each: from Winter Solstice to Rain Water it's Yang Dun, ju 1; from Rain Water to Grain Rain, Yang Dun 7; from Grain Rain to Summer Solstice, Yang Dun 4; from Summer Solstice to End of Heat, Yin Dun 9; from End of Heat to Frost's Descent, Yin Dun 3; from Frost's Descent to Winter Solstice, Yin Dun 6. As in the Chinese almanac, the day's solar term is taken at the end of the day, Beijing time: the day on which a term begins already belongs to the new block. The day pillar is calculated the same way as in the hour chart — by local solar time and with the selected Rat hour rule.

The choice between Chai Bu and Zhi Run applies only to the hour chart, so that field is hidden for the other charts. The solar time correction and the Rat hour rule change the day chart, because the day pillar depends on them, but not the month and year charts: the month and year change at the exact moment of a solar term, and the calculator compares that moment with clock time. That's why these fields are hidden for the month and year charts as well.

Schools disagree. For the month chart, books give other correspondences too: some swap the groups 子午卯酉 and 寅申巳亥, others use ju 7, 1 and 4 instead of 1, 4 and 7, and some programs take the ju from the monthly flying star, so it changes every month. We chose the rule that has a consistent worked example and under which the yuan follow one another in order: upper, middle, lower. For the day chart there are even more methods: blocks may start on the 甲子 day nearest to the solstice, or the ju may be taken from the solar term and the five-day yuan, as in the hour chart. There are also separate systems of day charts: Jin Han Yu Jing (“Golden Casket and Jade Mirror”) and the 120-ju system with the Tai Yi stars. The calculator builds the day chart only by the method described above.

We tested the calculation on three worked examples: the year 2004 (甲申, Yin Dun 7), the 辛未 month of 2004 (Yin Dun 4) and a 丁巳 day between Summer Solstice and End of Heat (Yin Dun 9). Both plates, the stars, doors and deities matched cell for cell. The year charts matched the independent atopx/qimen library on more than a thousand moments, including the minutes before and after Lichun. For month and day charts, that library chooses the ju by different rules, but when the ju is the same, the plates match.

The Nine Stars

Eight Doors

The doors are the most practical part of the chart: they are used to choose which direction to set out in and when to start a venture. The eight deities — Chief, Snake, Moon (Tai Yin), Six Harmony, White Tiger, Dark Warrior, Nine Earth and Nine Heaven — refine who or what helps and hinders.

An Honest Look at the Method

Qi Men Dun Jia is attributed to ancient generals, but the rules that have come down to us took shape in the Song and Ming dynasties. The system is calculated precisely — from the solar terms and the sixty-day cycle — but its predictive power has not been tested.

Use the chart as a traditional way to choose a time and direction for things where it does no harm. Decisions about health, money and safety are not made this way.

Related in This Section

• I Ching
• Chinese Calendar
• Chinese Hours
• Flying Stars
• Travel Direction
• Da Liu Ren
• Date Selection

Frequently asked questions

Which system should I choose — Chai Bu or Zhi Run?

The one your teacher or book uses. Chai Bu is more widespread today and easier to check; Zhi Run is considered more classical. If the systems give different ju, the calculator shows both.

Why does the chart depend on location?

The hour is counted in local true solar time: in Moscow, solar noon comes at about 12:30 clock time. You can turn the correction off if your school uses clock time.

Can I build a chart for a past or future time?

Yes, for any date from 1902 to 2099: choose the date and time in the form.

How do the day, month and year charts differ from the hour chart?

The plate is the same, but the day, month or year pillar takes the place of the hour pillar, and the ju is chosen by its own rules. Traditionally, the hour chart is used to choose a time within a day, the day chart to choose a day, and the month and year charts to assess the month and year as a whole.

Why does another program show a different chart for the month or day?

Schools choose the ju for these charts in different ways: for the month there are different correspondences between the year branch and the ju, and for the day there are several ways of dividing the year into blocks. The calculator's rules are described in the “Day, Month and Year Charts” section; check against the school you're studying.