This work explores the relationship between time, temporality, and power by utilizing interactions between Jesuit missionaries and the Ming and Qing governments of late imperial China as a case study. It outlines the complex relationship between knowledge of celestial mechanics, methods of measuring the passage of time, and the tightly controlled circumstances in which that knowledge was allowed to operate. Just as the Chinese courts exercised authority over time and the heavens, so too had the Catholic Church in Europe. So as messengers of God’s authority, the Jesuits identified the importance of astronomical and temporal authority in Chinese culture and sought to convey the supremacy of Christianity through their mastery of the stars and negotiate positions of power within both imperial governments.