section_path: History/Lunisolar calendars by dynasty/Ming and Qing Shíxiàn calendar
section_name: Ming and Qing Shíxiàn calendar
paragraph_text: Ming and Qing Shíxiàn calendar
  
  From 1645 to 1913 the Shíxiàn or Chongzhen calendar was developed. During the late Ming dynasty, the Chinese Emperor appointed Xu Guangqi in 1629 to be the leader of the Shixian calendar reform. Assisted by Jesuits, he translated Western astronomical works and introduced new concepts, such as those of Nicolaus Copernicus, Johannes Kepler, Galileo Galilei, and Tycho Brahe; however, the new calendar was not released before the end of the dynasty.
  
  In the early Qing dynasty, Johann Adam Schall von Bell submitted the calendar which was edited by the lead of Xu Guangqi to the Shunzhi Emperor. The Qing government issued it as the Shíxiàn (seasonal) calendar. In this calendar, the solar terms are 15° each along the ecliptic and it can be used as a solar calendar. However, the length of the climate term near the perihelion is less than 30 days and there may be two mid-climate terms. The Shíxiàn calendar changed the mid-climate-term rule to "decide the month in sequence, except the intercalary month."
  
  The present "traditional calendar" follows the Shíxiàn calendar, except: