How to calculate the lunar solar terms?

The traditional method of dividing the four seasons according to the lunar calendar in China takes four solar terms as the starting point of the four seasons and the bisector and two solstices as the midpoint.

For example, in spring, beginning of spring is the starting point, spring is the midpoint, and long summer is the end point. The long summer is the starting point of summer, the midsummer solstice is the midpoint, and beginning of autumn is the destination. Autumn begins in early autumn and ends in early winter. In winter, beginning of winter is the starting point, the winter solstice is the midpoint, and beginning of spring is the destination.

Related introduction:

Twenty-four solar terms are not only the time criterion promulgated by successive governments, but also the compass to guide agricultural production and to predict cold, warm, snow and rainy days in people's daily life. In the field of international meteorology, the 24 solar terms are known as "the fifth invention of China". 2016165438+1October 30th, 24 solar terms was officially listed in UNESCO? List of representative works of human intangible cultural heritage.

Extended data

The four seasons on the earth are first manifested as an astronomical phenomenon, which is not only the periodic change of temperature, but also the periodic change of the length of day and night and the height of the sun. Of course, the change of the length of day and night and the height of the sun at noon determines the change of temperature.

The gradual changes of the four seasons are not uniform all over the world. It is summer in the northern hemisphere and winter in the southern hemisphere. The northern hemisphere changes from warm to cold, and the southern hemisphere changes from cold to hot. The length of day and night and the height of the sun change periodically in different seasons.

The current "24 solar terms" take the earth's revolution around the sun as a cycle, which basically summarizes the different positions of the sun on the ecliptic at different times of the year, the exact time when cold comes and summer goes, and the laws of some natural phenomena such as phenology in nature.

Baidu encyclopedia-four seasons