As a traditional calendar used in China, the lunar calendar is also called the calendar of the Xia Dynasty, middle calendar, and the old calendar. People also call it lunar ephemeris. In the calendar, months are decided according to the strict synodic periods. Besides, by means of an intercalary month, the average length of a year is made similar to that of tropical year. Hence the lunar calendar is characteristic of both the lunar month and solar year. Accordingly, it is in essence a luni-solar calendar. In China, it is the lunar calendar that decides most of the traditional festivals. For instance, the Spring Festival is on the 1st day of the 1st lunar month, the Lantern Festival on the 15th day of the 1st lunar month, the Dragon Boat Festival on the 5th day of the 5th lunar month, and the Mid-Autumn Festival on the 15th day of the 8th lunar month. In addition, Chinese farmers basically work according to the lunar calendar as well.
