2022. 12.7 What is the lunar calendar?

Lunar calendar, the modern calendar in China, 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.

China traditional calendar

Calendar is a rule to measure a long time interval, judge climate change and predict the arrival of seasons according to the natural laws of astronomical changes. According to calendar year, calendar year and calendar month, it is divided into ephemeris, solar calendar, lunar calendar and yin-yang calendar. There are four general calendars: the lunar calendar (monthly calendar), the solar calendar (solar calendar), the ephemeris (Beidou calendar) and the combined calendar of yin and yang.

Shuotian is the first day of the lunar month, which means that the first day of each lunar month must be Shuotian. Each lunar month reflects a complete cycle of lunar phase change, so it belongs to the lunar part of the yin-yang calendar. The twenty-four solar terms of the lunar calendar reflect the different positions on the earth's orbit around the sun, that is, the tropic year cycle, so it belongs to the solar calendar part of the lunar calendar.

Baidu Encyclopedia-Lunar Calendar