The origin of the name of long summer and the origin of long summer solar terms.

1. The long summer solar term was established at the end of the Warring States Period (239 BC), indicating the change of seasons, that is, the day when the summer of the four seasons begins in a year. Therefore, it is called "Long Summer".

2. The solar term in the long summer begins in April 1 every year, and the solar calendar lasts from May 5th to 6th. It is the first summer of the lunar calendar when the sun reaches 45 degrees.

The long summer can be regarded as bidding farewell to spring, which is the beginning of summer. When the temperature rises significantly, the summer heat approaches, thunderstorms increase and crops enter the peak season, people usually regard the long summer as an important festival.

4. The long summer is also the beginning of the main calendar. "Fighting refers to the southeast, and Wei is the long summer." It means that everything here has grown up, so it is named Changxia. "Summer" in long summer means "big", and "long summer" means that plants planted in spring grow upright. Spring is born, summer grows, autumn harvest, and winter storage. Summer is the best season for many crops to grow vigorously.