《汉书·志·律历志下》
《春秋历》上说，周文王四十二年十二月丁丑朔旦冬至，是孟统的二会首。
《春秋历》，周文王四十二年十二月丁丑朔旦冬至，孟统之二会首也。
The "Spring and Autumn Calendar" says that in the forty-second year of King Wen of Zhou, on the first day of the winter solstice after the first day of the winter solstice, it is the second meeting of Mengtong.