An ancient divination department for emperors.

Official signature. Observe the astronomical phenomena and calculate the solar calendar. Taishiling has been in charge of astronomical calendar since Qin and Han Dynasties. Sitiantai was set up in the Tang Dynasty. Song and Yuan Dynasties were called Tianjian Department, which was juxtaposed with Taishi Bureau and Taishi Museum. Yuan also set up a meeting department. Ming and Qing dynasties changed their names to Qin, and set up a supervisor and a deputy supervisor.