Does the summer calendar refer to the lunar calendar or the solar calendar?

One of the ancient calendars in China. According to legend, it was built in Xia Dynasty, hence its name. Also known as lunar calendar, lunar calendar and old calendar. Actually, it's a kind of lunar calendar. It takes silver moon as the beginning of a year, and the moon goes around the earth as January, December or March as a year. Each month is divided into 30 days and 29 days. Its leap method is: three years leap, five years leap and nineteen years leap. "The Book of the Later Han Dynasty": "In the fourteenth year of Yongyuan, Huo Rong said," The official leakage rate has increased or decreased for a while on the ninth day, which does not correspond to heaven. Or the time difference is 2: 30, not as dense as the summer calendar. "Book of Song Dynasty": "It is especially against the law of many people to March westward in the seventh summer calendar. Liu Xiang thought it was done by later generations. This is also a suspicious basis. "