《史记·十二本纪·孝武本纪》
于是黄帝计算未来的日子，用算策推算朔望，从那以后大概每二十年得初一早晨冬至，他一共做了二十次推算，共计三百八十年，黄帝成仙升天。 
于是黄帝迎日推䇲，后率二十岁得朔旦冬至，凡二十推，三百八十年。黄帝仙登于天。 
Thereupon, the Yellow Emperor calculated the days ahead and used counting methods to deduce new moons and full moons. From then on, every 20 years or so, the first day of the month would fall on the winter solstice. He made 20 such deductions, totaling 380 years, after which the Yellow Emperor ascended to heaven and became immortal.