How is the traditional chronology of China calculated?

Lunar calendar is a traditional calendar adopted by China, also known as summer calendar, middle calendar and old calendar. Some people call it the lunar calendar. It uses the strict lunar cycle to determine the month, and sets the leap month to make the average length of a year close to the tropic year, which has the attributes of lunar month and solar year, so it is essentially a kind of yin-yang calendar.

The lunar calendar is based on the law of the moon's movement: the moon's orbit is called the white road, and the white road and the ecliptic are two great circles on the celestial body, which intersect at five degrees and nine minutes. The moon goes around the earth once, and people appear on the ecliptic twice, lasting 7 hours and 43 minutes 1 1.5 seconds on the 27th. This is the time required for the moon to go around once, which is called "the moon". Only when the moon revolves around the earth, the position of the earth also changes. The forward count is more than 27 degrees, and the moon runs 13 degrees 15 minutes every day, so it takes 12: 44: 2.8 to return to the moon on the 29th, which is called "the first moon", and it is called the moon according to custom, which means the first moon. After the founding of New China, Purple Mountain Observatory of Chinese Academy of Sciences assumed the role of the former censor and was responsible for compiling the perpetual calendar.