Four-in-four formula

Four unique formulas for four stations and four followers:

Li Si is beginning of spring, Changxia, beginning of autumn and beginning of winter; Four points refers to the day before the vernal equinox, autumnal equinox, summer solstice and winter solstice; The four wonders are vernal equinox, summer solstice, autumn equinox and winter solstice.

By studying the movement of nature and celestial bodies, the working people in ancient China divided a year into 24 solar terms, with four days off, mainly to remind people that some important days in daily life should be carried out according to the time nodes of natural laws.

Twenty-four solar terms are recorded on the calendar. People usually call beginning of spring, Changsha, beginning of autumn and beginning of winter "Li Si", and the day before "Li Si" is called "Decisive Day", which means "Decisive Day". The so-called "absolute", just like the literal meaning, means to be cut off, exhausted, and finished. After the four wonders, it is four, that is, spring and winter. When summer begins, spring ends; When autumn stands, summer has passed; Winter begins and autumn ends. In contrast, the word "Li" in "Si Li" is the beginning of arrival.