授时历








《授时曆》是中国古代曾经使用过的一种曆法，为元代郭守敬、王恂、许衡等人创制，因古语“敬授人时”而得名，从元朝至元十八年（西元1281年）开始实行。明朝所颁行的《大统曆》天文數據和推步方法，都依照授時曆[1]，惟《大统曆》不計算斗分差（不考慮回歸年古長今短。）；可說授時曆总共实行了402年。


《授时历》应用弧矢割圆术来处理黄经和赤经、赤纬之间的换算，并用招差术推算太阳、月球和行星的运行度数。《授时曆》采用统天曆的长度，365.2425日为一年，29.530593日为一月，与现在所使用的公曆的数值完全相同，但《授时历》比公历早推行301年。推算节气的方法是将一年的1⁄24作为一气，以没有中气的月份为闰月。它正式废除了古代的上元積年[2]，而逕取至元十八年為为历元，所定的数据全凭实测，打破古代製曆的习惯，是中国历法上的大变革之一。



参考文献





  1. ^ 邓文宽：《国家图书馆藏明代大统历日汇编》前言


  2. ^ 曲安京. 中国历法与数学. 2005. 



  • 席文：〈为什么《授时历》受外来的影响很小？〉。
























































































































































































































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