《宋书·志·卷十六》
尚书何偃议论说： 郑玄注《礼记》，引用《易经》说夏、商、周三朝的郊祀，一概都用夏历。
尚书何偃议： 郑玄注《礼记》，引《易》说三王之郊，一用夏正。
Shangshu He Yan said: Zheng Xuan's annotation in <Records of Rites> refers to the <Book of Changes>, and says that the  suburban sacrifices of the three dynasties of Xia, Shang and Zhou were all held in the first month of the Xia calendar.