The Spread and Influence of Season-Granting System in Korea and Japan

By comparing the spread and use of the traditional Chinese calendar Season-Granting System (Shoushi li 授时历) in Korea and Japan, this article analyzes the differences between the two countries in their motivations for, approaches to, and results of adopting the calendar. Korean adoption of the Season-Granting System was led by the government, motivated by certain political and diplomatic considerations, while during the Edo period the Japanese learned the calendar more out of technical considerations, with the participation of astronomers and calendrical scientists from both inside and outside of the government. Moreover, the Season-Granting System not only had an important impact on the development of the calendar in these two countries, but also its traditions of "accurate measurement" (jingce 精测) and "precise calculation" (misuan 密算) contributed to the improvement of astronomical instruments in Korea and the development of traditional Japanese mathematics (Wasan).