What month is long summer? How to calculate the arrival of long summer?

The origin of long summer in the twenty-four solar terms

When the solar term of long summer comes, it means that summer is about to begin. At this time, the temperature will rise obviously. When summer comes, crops will grow quietly, so summer is a growing season.

This season was established at the end of the Warring States period (239 BC), indicating the change of seasons, and it was the day when the four seasons were divided into summer according to the lunar calendar in ancient times. For example, The Interpretation of Yizhoushu Poems says: "On a long summer day, the sound is like cricket. On the fifth day, the earthworm came out. Another five days, Wang Guasheng. " That is to say, in this solar term, you can first hear the chirping of grubs (that is, slugs) in the field, then you can see earthworms digging in the soil, and then the vines of melon begin to climb and grow rapidly, which describes the phenological scene in early summer. "Twenty-four solar terms" said: "It was also the beginning of long summer, when Xia Zhishi was established and everything was false." The "false" here, that is, "big", means that the plants sown in spring have grown upright.

In the long summer, everything is thriving. The book "Eight Chapters of Lotus Life" written by the Ming Dynasty said: "On the day of summer dream, heaven and earth began to merge and everything was beautiful." At this time, the summer harvest crops entered the late growth stage, the winter wheat blossomed and filled, the rape was close to maturity, and the summer harvest crops were basically a foregone conclusion that year. Therefore, there is a saying in agricultural proverbs that "see summer in the long summer". Rice planting and management of other spring-sown crops have also entered a busy season. Therefore, China has always attached great importance to the long summer solar terms.