Concept of solar terms: What are beginning of spring, Changxia, beginning of autumn and beginning of winter collectively?

Together, it is called "four stands". "Reason" means the beginning. In ancient China, Li Si was considered as the beginning of the four seasons. The book of parallel calculation in Zhou Dynasty: "Four stands, the beginning of growth and collection." In other words, Li Si is the beginning of spring, summer, autumn harvest and winter storage.

Among the traditional twenty-four solar terms, beginning of spring, Changxia, beginning of autumn and beginning of winter are collectively called "Sili"; The day before beginning of spring, Changsha, beginning of autumn and beginning of winter was called "four unique days". In addition, the day before vernal equinox, summer solstice, autumn equinox and winter solstice is called "four departures from the sun".

Li Si refers to the four solar terms of beginning of spring, Changxia, beginning of autumn and beginning of winter, which represent the beginning of the four seasons respectively. "Stand" means to start. The Gregorian calendar is generally around February 4th, May 5th, August 7th and165438+1October 7th every year. "Li Si" indicates the beginning of the astronomical season. As far as climate is concerned, it is still in the last season. For example, the Yellow River Basin in early spring is still in the middle of winter.