乾卦六龙态的天文含义研究--《左传》"龙纪"历法钩沉

《左传》昭公四年的“龙纪”,是上古以苍龙星为历象的太阳历的记载。这个苍龙星星象在《易经》乾卦六爻爻辞中有形象的描述,根据寅月“见龙”、午月“跃龙”等记载,可知其观测年代当在夏代以前。这种借龙“以喻天之阳气”的龙纪历法流传至先秦秦汉,或称“易历”、“气历”;或称“律历”、“甲历”。它以天干记日,十日为旬,六旬为甲,六甲为岁,一岁360日;并通过不记在日序之内的56日的过年日使历年长度略等于回归年长度,从而形成了原始社会晚期一部较实用的历法。

A Study of the Astronomical Meaning of QIAN GUA LIU LONG TAI (six dragon shape in Qian trigram)

LONGJI(A Record of Dragon)appeared on the fourth year of Zao Gong from Zuo's Commentary,it is a record in solar calendar inwhich the Green Dragon Star is taken as a symbol.When this kind of calendar had passed down to Qin-Han times,it was called either "YILI","QILI" or "LULI","JIALI".It adopted the Heavenly Stems to date time. According to the calendar,ten days make a Xun,six Xun make a jia and six jia make a year, a year is make up of 360 days. It was a practical calendar in late primitive society.