《明史·志·卷七》
只有明的《大统历》，实际上就是元的《授时历》，袭用了二百七十多年，未曾改变历法。
惟明之《大统历》，实即元之《授时》，承用二百七十馀年，未尝改宪。
Only the "Datong Calendar" of the Ming Dynasty was actually the "Shoushi Calendar" of the Yuan Dynasty, which was used for more than 270 years without changing the calendar.