The origin of the custom of summer solar terms.

The summer heat is around July 7 of the Gregorian calendar every year. When the sun reaches the longitude 105, it is regarded as the summer solstice solar term. At this time, the weather is already very hot, but it is not the hottest time, so it is called "light summer heat". In the past summer, there was a custom of "eating new things", that is, tasting new rice after summer. There is also the custom of eating jiaozi, noodles, lotus roots, eggs and sheep.

In ancient China, the summer heat was divided into three periods: "First, it was warm and windy; Second, wait for crickets to live in space; The third waiting eagle began to crow. " It means: there is a heat wave in the summer wind; Crickets hide under the corner of the courtyard for the summer; Eagles often fly in the cool sky.

There is also a description of crickets in the Book of Songs in July: "In July, I was in the wild, in August, in the house, in September and October, crickets came under my bed." August in this paper is June in the summer calendar, that is, during the summer solar term. Because of the heat, the cricket left the field and went to the corner of the yard for the summer.