section_path: History/Lunisolar calendars by dynasty/Qin and early Han dynasties
section_name: Qin and early Han dynasties
paragraph_text: Qin and early Han dynasties
  
  After Qin Shi Huang unified China under the Qin dynasty in 221 BCE, the Qin calendar (秦曆; 秦历) was introduced. It followed most of the rules governing the Zhuanxu calendar, but the month order was that of the Xia calendar; the year began with month 10 and ended with month 9, analogous to a Gregorian calendar beginning in October and ending in September. The intercalary month, known as the second Jiǔyuè (後九月; 后九月), was placed at the end of the year. The Qin calendar was used going into the Han dynasty.