2023. 1 1.6 What is the lunar calendar?

Lunar calendar is the current modern calendar in China, which belongs to the combined calendar of yin and yang, that is, the combined calendar of lunar calendar and solar calendar. According to the change cycle of the moon phase, each moon phase changes to one month, and the reference solar year is the length of one year, 24 solar terms are added, and leap months are set to make the average calendar year adapt to the tropic year. The combination of lunar calendar and solar calendar in lunar calendar forms the method of combining yin and yang. Because of the use of "Xia Zheng", it was called Li Xia in ancient times.

Lunar calendar is a new calendar used after 1970, and its years are divided into flat years and leap years, with flat years 12 months and leap years 13 months. Month is divided into big month and small month, with 30 days in big month and 29 days in small month, and the average calendar month is equal to the full moon.

The 24 Solar Terms

Twenty-four solar terms is a special festival in China calendar to express the change of natural rhythm and establish "December architecture", which can accurately reflect the change of natural rhythm and contains a long cultural connotation and historical accumulation. The twenty-four solar terms were originally formulated according to the changes of stars. The Big Dipper rotates circularly, and bucket handle rotates clockwise once, which is called one of the "years old". At present, the establishment of the twenty-four solar terms is based on the "annual apparent movement of the sun", which is also the degree of the yellow meridian of the sun.

Although they are established in different ways, the cause of the struggle is that the earth revolves around the sun, so the time of their intersection is basically the same. In the historical development, the 24 solar terms have been incorporated into the lunar calendar and become an important part of the lunar calendar. The month of the lunar calendar basically corresponds to the twelve qi, and the twelve solar terms can appear in the second half of last month and the first half of this month. "Twenty-four solar terms" is an important part of the long history and culture of the Chinese nation and embodies the historical and cultural essence of Chinese civilization.