Yisi Zhan-Tang Dynasty-Li Chunfeng

This book is a comprehensive astrological work, written later in the first year of Xianqing of the Tang Dynasty (AD 656). As for the title of the book, why is it named "Yi Si Zhan" after Yi Si in the Sixty Years? Lu Xinyuan, a bibliophile in the Qing Dynasty, explained: "In the year of Yisi in the Shangyuan Dynasty, on the first day of the eleventh month, at midnight on the winter solstice, the sun and the moon are like a pair of stones, and the five stars are like beads, so it is named after it." Lu Xinyuan believed that Li Chunfeng had calculated the accurate calendar year to be the year of Yisi, so he named the book after it to show that his words were accurate and trustworthy. Lu Xinyuan's explanation can be summarized as one.