section_path: History/Lunisolar calendars by dynasty/Yuan dynasty Shòushí calendar
section_name: Yuan dynasty Shòushí calendar
paragraph_text: Yuan dynasty Shòushí calendar
  
  The Yuan dynasty Shòushí calendar (授時曆; 授时历; ' season granting calendar ') used spherical trigonometry to find the length of the tropical year. The calendar had a 365.2425-day year, identical to the Gregorian calendar.