According to legend, during the period of Emperor Wu of the Western Han Dynasty, Emperor Wu of the Han Dynasty incorporated the 24 solar terms into the taichu calendar Law as a supplement to guide the agricultural calendar. At that time, the longest sun shadow and the shortest day in the Yellow River valley were measured by the method of measuring the sun shadow with soil gauge, and this day was regarded as the winter solstice, and the winter solstice was the starting point of the twenty-four solar terms. Divide the winter solstice and the next winter solstice into 24 equal parts, each equal part represents a node, each node is a solar term, and the interval between each solar term is 15 days. According to Tugui's method of measuring the sun shadow, the winter solstice is listed as the first of the 24 solar terms, starting from the winter solstice and ending with heavy snow.
Now the latest twenty-four solar terms are as follows: Spring rain shocks spring and bright valley days, summer is full and summer is hot. Autumn dew, autumn frost, little snow in winter and cold in winter. This solar term song is easy to understand. It fully shows the 24 solar terms in people's minds with fluent and dialect language characteristics. The solar terms and the Song Dynasty cover four seasons throughout the year, which basically reflects the specific time of the alternation of four seasons throughout the year and some laws of food exchange in nature.
The twenty-four solar terms have now been remembered by China people, especially farmers in China. This song "Twenty-four solar term song" is not only their formula for sowing and harvesting crops, but also a key to remember. I believe that every farmer in China can recite this twenty-four solar term song. In just 24 solar term song, the whole poem can be shortened to 28 words. Every word is accurate, and every word makes the finishing point.
Spring is beginning of spring, rain is rain, surprise is surprise, spring is vernal equinox, clear is clear, valley is Grain Rain, summer is long summer, full of small, busy is mango, summer is summer solstice, summer is small summer and big summer? Every word in the song seems to have its own life, and each word represents a kind of life.
A short poem explains to people the changes of seasons and the laws of nature, which is really the crystallization of human wisdom.