汤若望
The Chongzhen calendar () or Shixian calendar () was the final lunisolar Chinese calendar. It was developed by the Jesuit scholars Johann Schreck and Johann Adam Schall von Bell with Xu Guangqi from 1624 to 1644, and was dedicated to the Chongzhen Emperor. When he died a year after it was released, it was propagated in the first year of the Qing dynasty by the Shunzhi Emperor, who changed its name to Shíxiàn calendar. The calendar was used from the early Qing period into the modern era.