How is the long summer solar term calculated, and the origin of the long summer solar term?

1. As early as the Eastern Zhou Dynasty, the Spring and Autumn Period and the Warring States Period, the working people of the Han nationality had the concept of "the sun comes from the south to the north". Subsequently, people divided the year into 24 equal parts according to the natural phenomena such as the running position of the sun and the moon at the beginning and middle of the month, the weather and the growth of animals and plants. And give each equal part a proper noun, that is, twenty-four solar terms. By the end of the Warring States Period, solar terms had eight names: beginning of spring, Equinox, Long Summer, Summer Solstice, beginning of autumn, Equinox, beginning of winter and Winter Solstice.

2. Long summer is the seventh solar term among the twenty-four solar terms and the first solar term in summer. The festival of long summer falls on May 05-07 of the Gregorian calendar every year, when the bucket handle of the Big Dipper points to the southeast and the longitude of the sun reaches 45. Every year around the first day of April, people have ushered in a relatively large solar term, long summer. This grand day was set up by people to welcome the hot summer. In ancient times, there was a clock that pointed to time. When its handle points to the southeast, it is the season of long summer, because everything will absorb the essence of the sun and the nutrition of the earth at this time, so it is the best time to grow. Long summer represents a simple way to say goodbye to spring and welcome summer.