馬王堆帛書《刑德》、《陰陽五行》諸篇曆法研究──以《陰陽五行》乙篇為中心

On the Calendars in the Mawangdui Xingde and Yinyang Wuxing: Centered on the Yinyang Wuxing B

數術文獻中的曆法應包含三個層次，即「編纂使用曆法」、「貞卜適用曆法」以及「實際所用曆法」。通過對馬王堆帛書《陰陽五行》乙篇〈太陰刑德大游圖〉東北角文字的復原，可知該篇「編纂使用曆法」是一種歲實取三百六十六日的曆法。而該篇「實際所用曆法」則是取歲實為三百六十五又四分之一日的顓頊曆，與「編纂使用曆法」每年有四分之三日的誤差。由於曆法誤差每八年積累為六日，帛書〈刑德占〉章中神煞「德」的遷徙日期每隔八年就會滯後六日，占書的編纂者必須對「德」的推算方式作出調整，所以才將刑德大游的運行由「日至後之子午卯酉」改為「日至後七日之子午卯酉」。利用此曆法誤差，可以算出《陰陽五行》乙篇抄寫所據底本的實際使用時間為漢高祖十一年前後。同時還可推測，「刑德大游遷徙日期」的創立時間，約在秦二世元年（公元前209年）至漢高祖六年（公元前201年），甚至有可能就是以秦二世元年冬至日壬子這一特定時間節點編製的。《陰陽五行》乙篇的許多神煞是依據「編纂使用曆法」編排的。「刑德大游」、「刑德小游」、「年上朔」、「氣上朔」、「兇」、「刑日」等神煞的運行週期，或是三百六十六日的約數六日、六十一日，或是六日、六十一日、六十日（一甲子）的最小公倍數三千六百六十日（十年）。這些神煞在此曆法的支配下，形成了嚴密的數術系統。

The calendar in occult texts should have included three levels: the calendar used for compilation, the calendar appropriate for divination, and the calendar in actual use. Through a reconstruction of the text on the northeastern corner of the Taiyin xingde dayou tu (the picture of the great travelling of taiyin, xing [punishment] and de [virtue]) in Mawangdui Yinyang wuxing B, we can know that while the “calendar used for compilation” in this manuscript has 366 days in a tropical year, its “calendar in actual use” is based on the Zhuanxu calendar that has 365¼ days in a tropical year, resulting in a difference of ¾ days between the two calendars. Since the accumulated calendrical difference in eight years is six days, the migrating date of the calendrical spirit de will be six days behind every eight years in the “divination of xing and de” section. The compiler of this divination manual had to adjust the method of calculation. Therefore he changed “the zi, wu, mao, and you days after the solstice” into “the zi, wu, mao, and you days seven days after the solstice” in the “great travelling of xing and de.” We can use this calendrical difference to figure out that the master copy of the Yinyang wuxing B was being used around the 11th year of the High Ancestor of Han (i.e. Liu Bang, 196 BCE). At the same time, we can surmise that the migrating date of the “great travelling of xing and de” was invented sometime between the 1st year of the Second Emperor of Qin (209 BCE) and the 6th year of the High Ancestor of Han (201 BCE), probably based on the winter solstice (renzi) of 209 BCE. Many calendrical spirits in Yinyang wuxing B were based on the “calendar used for compilation.” The cycling periods of the “great travelling of xing and de,” “small travelling of xing and de,” “nian shangshuo (shangshuo of the year),” “qi shangshuo (shangshuo of the solar terms),” “xiong (ominous),” and “xingri (punishment day)” are either 6 days and 61 days (divisors of 366) or 3660 days (10 years, the least common multiple of 6 days, 61 days, and 60 days [a sexagenary cycle]). These calendar spirits formed a rigorous occult system.