The calendars of ancient China were different from the other luni-solar calendars: there were Twenty-four Solar terms, and they had been combining with the Gan-Zhi ( a sexagenary cycle) to number the time. At the latest, our forefathers used the way of numbering the days with Stem and Branch during the period of Yin-Shang Dynasty. Nevertheless, when did the way of numbering the years with Gan-Zhi start, different people have different versions. Silk Book Xing De unearthed at Mawangdui confirmed that the way of numbering the years with Gan-Zhi had been used in the early Han Dynasty. However, according to the records of historical documents and the Silk Book Wu Xing Zhan ( treatise on astrology ), We know that the methods of the way of numbering the years were different then. The annals recorded by the Stems and Branches were emended by the Eastern Hah schoIars and traced back to remote antiquity.
