What is the origin and formulation of the lunar calendar in China?

Lunar calendar is a traditional calendar in China, also known as lunar calendar, Chinese calendar, summer calendar, Han calendar and national calendar. It is a kind of lunar calendar. It takes the cycle of the moon phase as the length of a month and the length of the year of the return of the sun as the length of a year. By setting leap months, the average calendar year adapts to the tropic year.

According to the Chinese ancestor Xuanyuan Huangdi ascended the throne as the first year, our traditional calendar is 2697 years earlier than the Gregorian calendar, and AD +2697 is the year of our traditional calendar. There are many records about the lunar calendar in ancient books and Oracle Bone Inscriptions, and a large number of historical records record that the lunar calendar began in the era of the Yellow Emperor. It is generally believed that the calendar rule of the integration of yin and yang in the lunar calendar originated from the Shang Dynasty.

Commonly used terms

Zodiac: It is the coordinate value used to determine the position of celestial bodies (celestial spheres) on the earth in the ecliptic coordinate system. In this system (celestial sphere), the earth is divided into two hemispheres by the ecliptic plane. When the sun moves to longitude 0, it is the vernal equinox; When it moves to the longitude of 90, it is the summer solstice; When it moves to 180, it is the autumnal equinox; When the temperature rises to 270 degrees, it is the winter solstice.

The first day of the first month of the lunar calendar is usually called "the first day of the year". In fact, strictly speaking, "year" is a unique concept in the official calendar, which means "taking pictures", also known as Tai Sui. The original meaning of "the first year of the year" is the first day of the first month of the country (Tai Sui), that is, beginning of spring. The lunar calendar changes into one month according to the phases of the moon, and the first day of the first lunar month is often called "Yuanshuo".

Homogeneous level: the uneven motion of the sun on the ecliptic is not considered in the calculation, and the first anniversary (tropic year) is divided into 24 solar terms, and the average number of days between the two solar terms is 15.22 days.

The above contents refer to Baidu Encyclopedia-? China traditional calendar