Early Qing Western Calendar Reform

Timeline

1. 1645–1650Astronomical Bureau, Beijing · BeijingAdam Schall von Bell directed compilation of the Shixian calendar, using the Tycho system and European astronomical calculations; the Qing court formally promulgated it and reorganized the Astronomical Bureau, replacing the Ming traditional calendar framework with Western methods.
2. 1664–1665Beijing · BeijingYang Guangxian and others initiated the Calendar Case, accusing the Western calendar of violating precedent; Schall von Bell and the Astronomical Bureau were purged, the Shixian calendar was temporarily suspended, and the dispute between traditional and Western methods intensified.
3. 1668–1670Astronomical Bureau, Beijing · BeijingFerdinand Verbiest prevailed over native methods in observational tests; the Kangxi Emperor restored the Shixian calendar and appointed him Director of the Astronomical Bureau, making Western calendar calculations and eclipse predictions the national standard again.