The Mystic Pivot of Earthly Order: A Study on the Ancient Origins of the Six Combinations and Qi Transformations of the Twelve Earthly Branches
This article offers an in-depth investigation into the pre-Qin, high-antiquity origins and inner rationale of the Six Combinations and their Qi transformations among the Twelve Earthly Branches (e.g., Zi-Chou combining to transform into Earth). Through textual examination of the Earthly Branches' origins, their connection with Jupiter's orbital cycle, the correspondences between the twelve months and the twelve sovereign hexagrams, and the spatial positioning of the four Earth-branches at the four inter-cardinal directions, the essay reveals the profound astronomical and yin-yang philosophical underpinnings of the Earthly Branch system as a cornerstone of Chinese metaphysical arts.
Chapter Seven: The Six Combinations, Qi Transformation, and Ancient Calendrics
Section 1: Monthly Establishments and the Six Combinations
The ancient calendar reckoned months by the Dipper's establishment (doujian), with the Dipper's handle completing one rotation per year, pointing each month to a specific Branch direction.
The sequence of monthly establishments: first month establishes Yin, second Mao, third Chen, fourth Si, fifth Wu, sixth Wei, seventh Shen, eighth You, ninth Xu, tenth Hai, eleventh Zi, twelfth Chou.
The Six Combination pairings correspond exactly to:
- Zi-establishment month (11th) and Chou-establishment month (12th)
- Yin-establishment month (1st) and Hai-establishment month (10th)
- Mao-establishment month (2nd) and Xu-establishment month (9th)
- Chen-establishment month (3rd) and You-establishment month (8th)
- Si-establishment month (4th) and Shen-establishment month (7th)
- Wu-establishment month (5th) and Wei-establishment month (6th)
Note an important symmetry:
- 11th + 12th = 23 (by month-order)
- 1st + 10th = 11
- 2nd + 9th = 11
- 3rd + 8th = 11
- 4th + 7th = 11
- 5th + 6th = 11
Except for the first pair (Zi-Chou), the remaining five pairs sum to 11. But if the eleventh month is recorded as -1 and the twelfth as 0 (taking the first month as 1), the underlying numerical pattern reflects the astronomical symmetry centered on the winter solstice discussed above.
Section 2: Intercalation and the Six Combinations
A core problem of ancient calendrics was intercalation (zhirun). A lunar year of 354 days (12 x 29.5 approximately equals 354) falls about 11 days short of a solar year of 365.25 days. Hence every two or three years an intercalary month was inserted to keep the lunar and solar calendars roughly aligned.
The Shangshu, "Canon of Yao":
"The period is three hundred and sixty-six days. By means of an intercalary month, fix the four seasons and complete the year" (qi san bai you liu xun you liu ri, yi run yue ding si shi cheng sui).
"Three hundred and sixty-six days" (the ancients rounded up); the intercalary month adjusts so the seasons do not drift.
What connection does the placement of intercalary months have with the Six Combinations and Qi Transformation$21
In the ancient nineteen-year-seven-intercalation method (the "Rule" or zhang method), nineteen solar years equal exactly 235 synodic months. Of these 235 months, 228 (19 x 12) are regular months and 7 are intercalary. The placement of intercalary months must ensure that the sun-moon conjunction zones do not deviate too far.
The Six Combination method -- pairing months symmetric about the winter solstice -- provides a way to verify calendrical accuracy. If the calendar is accurate, the solar positions of the two months in a combination should maintain their symmetry; if deviation appears, adjustment (intercalation) is needed.
The Zuozhuan, first year of Duke Wen:
"The former kings, in rectifying the seasons, trod upon the starting point at the beginning, raised the standard at the center, and assigned the remainder at the end" (lu duan yu shi, ju zheng yu zhong, gui yu yu zhong).
"Trod upon the starting point at the beginning" -- taking the winter solstice as the year's starting point. "Raised the standard at the center" -- using the equinoxes as mid-point verification. "Assigned the remainder at the end" -- placing accumulated surplus days at year's end (intercalation). The method of "raising the standard at the center" relates to the Six Combinations' symmetry -- verifying the symmetric relationship between the equinox months (Mao and You, part of the Chen-You combination); if these deviate, adjustment is needed.
Section 3: The Grand Inception Calendar and the Six Combinations
Around the Han dynasty, calendrics grew increasingly precise. The Hanshu, "Treatise on Pitch-Pipes and the Calendar," details the formulation and principles of the Grand Inception Calendar (Taichu Li). It contains a passage closely related to the Six Combinations:
"The movement of Heaven proceeds from the north, turning to the right. The sun's rate moves one degree to the right per day. The moon's rate is thirteen degrees and seven-nineteenths to the right per day... The sun and moon conjoin at the beginning of the Establishing Star; the sun moves one degree per day, the moon thirteen degrees and seven-nineteenths. After twenty-nine days and 499/940 of a day, they conjoin again."
This passage details the rates of solar and lunar motion. The sun travels one degree per day, the moon thirteen and a fraction; they conjoin again after twenty-nine and a fraction days. The different speeds of sun and moon cause the conjunction zone to shift approximately 30 degrees (one palace) each month.
In a year, twelve conjunctions occur in twelve different mansion zones. And the conjunction zones of two months in a Six Combination are precisely symmetric about the winter solstice point. This is the specific manifestation of the Six Combinations' astronomical basis within the calendrical system.
Section 4: The Twenty-Eight Mansions and the Six Combinations
The Twenty-Eight Lunar Mansions (ershiba xiu) are a key framework of ancient astronomy, dividing the sky near the ecliptic into twenty-eight zones. Their pairing with the twelve Earthly Branches:
| Branch | Corresponding Mansions |
|---|---|
| Zi | Xu (Emptiness), Wei (Rooftop) |
| Chou | Dou (Dipper), Niu (Ox) |
| Yin | Wei (Tail), Ji (Winnowing Basket) |
| Mao | Di (Root), Fang (Chamber), Xin (Heart) |
| Chen | Jiao (Horn), Kang (Neck) |
| Si | Yi (Wings), Zhen (Chariot Platform) |
| Wu | Liu (Willow), Xing (Star), Zhang (Extended Net) |
| Wei | Jing (Well), Gui (Ghost) |
| Shen | Zi (Turtle Beak), Shen (Three Stars) |
| You | Wei (Stomach), Mao (Pleiades), Bi (Net) |
| Xu | Kui (Striding Legs), Lou (Bond) |
| Hai | Shi (Hall), Bi (Wall) |
(This correspondence varies slightly across eras; the approximate matchings are given here.)
Verifying the mansion symmetry of the Six Combinations:
- Zi-Chou: Zi in Xu-Wei, Chou in Dou-Niu. Adjacent, both near the winter solstice point (approximately at the initial degree of Niu), symmetric about it. Confirmed.
- Yin-Hai: Yin in Wei-Ji, Hai in Shi-Bi. Wei-Ji are about 30-60 degrees east of the winter solstice point; Shi-Bi are about 30-60 degrees west. Symmetric. Confirmed.
- Mao-Xu: Mao in Di-Fang-Xin, Xu in Kui-Lou. Di-Fang-Xin about 60-90 degrees east; Kui-Lou about 60-90 degrees west. Symmetric. Confirmed.
- Chen-You: Chen in Jiao-Kang, You in Wei-Mao-Bi. Jiao-Kang about 90-120 degrees east; Wei-Mao-Bi about 90-120 degrees west. Symmetric. Confirmed.
- Si-Shen: Si in Yi-Zhen, Shen in Zi-Shen. Yi-Zhen about 120-150 degrees east; Zi-Shen about 120-150 degrees west. Symmetric. Confirmed.
- Wu-Wei: Wu in Liu-Xing-Zhang, Wei in Jing-Gui. Liu-Xing-Zhang about 150-180 degrees east of the winter solstice point; Jing-Gui about 150-180 degrees west, symmetric about the summer solstice point (complementary symmetry about the winter solstice point). Confirmed.
The mansion symmetry of all six combinations is perfectly consistent! This is the precise verification of the Six Combinations' astronomical basis within the Twenty-Eight Mansions system.