How to Select a Qimen Dunjia Hexagram Using the 24 Solar Terms
The main challenge in learning Qimen Dunjia is arranging the chart. Once you master the key techniques, though, it becomes manageable. The process has two stages: choosing the chart and laying it out.
The first stage is selecting the chart. Qimen Dunjia has nine Yang charts and nine Yin charts, for a total of eighteen. Use Yang charts from the winter solstice to the summer solstice, and Yin charts from the summer solstice to the winter solstice. Within each of the twenty-four solar terms, select a chart every five days (each term spans fifteen days). This yields three charts per solar term: the first five days are the Upper Yuan, the next five days are the Middle Yuan, and the last five days are the Lower Yuan. For Yang charts, add 6 to the Upper Yuan number to get the Middle Yuan, then add 6 again to get the Lower Yuan; if the result exceeds 9, subtract 9. For example, if the Upper Yuan is Yang 1, then 1 + 6 = 7 (Middle Yuan Yang 7); 7 + 6 = 13, and 13 - 9 = 4 (Lower Yuan Yang 4). If the Upper Yuan is Yang 8, then 8 + 6 = 14, and 14 - 9 = 5 (Middle Yuan Yang 5); 5 + 6 = 11, and 11 - 9 = 2 (Lower Yuan Yang 2). Yin charts follow the same pattern but subtract 6: subtract 6 from the Upper Yuan to get the Middle Yuan, then subtract 6 again to get the Lower Yuan; if the result drops below 1, add 9. For example, if the Upper Yuan is Yin 9, then 9 - 6 = 3 (Middle Yuan Yin 3); 3 - 6 = -3, and -3 + 9 = 6 (Lower Yuan Yin 6). If the Upper Yuan is Yin 5, then 5 - 6 = -1, and -1 + 9 = 8 (Middle Yuan Yin 8); 8 - 6 = 2 (Lower Yuan Yin 2). Once you know the Upper Yuan for each solar term, you can determine its Middle and Lower Yuan numbers.
To find the Upper Yuan number for each solar term, first determine the Upper Yuan numbers for the eight solar festivals. Among the twenty-four solar terms, the winter solstice, beginning of spring, spring equinox, beginning of summer, summer solstice, beginning of autumn, autumn equinox, and beginning of winter (the four “beginnings,” two solstices, and two equinoxes) are the eight festivals. Each festival sets the Upper Yuan for itself and the next two terms: the winter solstice governs Minor Cold and Major Cold; the beginning of spring governs Rain Water and Awakening of Insects; the spring equinox governs Qingming and Grain Rain; the beginning of summer governs Minor Fullness and Grain in Ear; the summer solstice governs Minor Heat and Major Heat; the beginning of autumn governs End of Heat and White Dew; the autumn equinox governs Cold Dew and Frost’s Descent; and the beginning of winter governs Minor Snow and Major Snow. The winter solstice, beginning of spring, spring equinox, and beginning of summer are Yang festivals; their Upper Yuan numbers increase by one and then two for the two terms they govern. For example, if the winter solstice Upper Yuan is 1, then Minor Cold is 2 and Major Cold is 3. If the beginning of spring Upper Yuan is 8, then Rain Water is 9 and Awakening of Insects is 1 (subtract 9 if the result exceeds 9). The summer solstice, beginning of autumn, autumn equinox, and beginning of winter are Yin festivals; their Upper Yuan numbers decrease by one and then two for the two terms they govern. For example, if the summer solstice Upper Yuan is 9, then Minor Heat is 8 and Major Heat is 7. If the beginning of autumn Upper Yuan is 2, then End of Heat is 1 and White Dew is 9 (add 9 if the result falls below 1). Once you know the Upper Yuan numbers for the eight festivals, you can derive the Upper Yuan numbers for all twenty-four solar terms.
To determine the start day for the Upper Yuan, you must also identify the first ten days of the lunar month, and then either follow the standard method or use the methods of receiving energy, transcending spirits, or adding leap days. Please refer to related articles for more information.