Shoushi li jing 授時曆經

Shoushi li jing 授時曆經 is a text highlighting calculation methods for the Shouli Calendar 授時曆 which was created by Guo Shoujing 郭守敬 (1231-1316) and Xu Heng 許衡 (1209-1281). The text was written by Xu.

It consists of seven parts calculating qi 氣 ("ether", "energy", "breath") and New Moon (Bu qishuo 步氣朔), ecliptic positions (bu falian 步發斂), the "motion" of the Sun (Bu richan 步日躔), the elongation of the Moon (Bu yueli 步月離), the culmination of stars (Bu zhongxing 步中星), conjunctions (Bu jiaohui 步交會), and the motions of the Five Planets (Bu wuxing 步五星).

The Shoushi li jing is included in Xu's collected writings Xu Wenzhenggong yishu 許文正公遺書.