;</i> (&#28450;&#26360; or <i>Book of Han</i>) further explains that the calendar used by the Qin dynasty was the Zhuanxu calendar, one of the <a href="guliuli.html">ancient six calendars</a> believed to have been used in the Warring States period (480 BCE &ndash; 222 BCE). However, it has been known for a long time that the dates computed by the Zhuanxu calendar do not agree with the dates appeared in the historical documents. They match more closely with those computed by the Yin calendar, another one of 