What is the origin of the lunar calendar?

The real calendar appeared in Tang Shunzong Yongzhen Garden about 1 100 years ago, and the royal calendar has been used in the palace. The first day is a page, recording the state, court events and the words and deeds of the emperor. The imperial calendar is divided into twelve volumes, each volume has the same number of pages as the number of days per month, and each page indicates the number of days and dates. Nowadays, popular calendars, whether paper publications, mobile phone applications or electronic desk calendars, usually include solar calendars, lunar calendars and dry calendars. Its formation has a process, starting from the date. As early as the Shang Dynasty, there were twelve calendar years in China, and twelve overtime days were adopted in the Spring and Autumn Period and the Warring States Period. From the end of the Western Han Dynasty to the present, we have been using dry branches to record the years. After the Tang Dynasty, the names of the calendars of the Five Dynasties began to be marked with branches. In the Northern Song Dynasty, the ten branches and twelve branches were combined with time. At this point, the calendars of trunk and branch are marked with trunk and branch, and the trunk and branch are becoming more and more complete.