How to better understand the turn of summer and autumn? From what month to what month every year? Please indicate the solar or lunar calendar. Thank you very much.

According to the theory of 24 solar terms, beginning of autumn is the summer before the festival and the autumn after the festival. Beginning of autumn is the turn of summer and autumn.

The Mid-Autumn Festival begins on August 7th or 8th of the Gregorian calendar every year, which is basically unchanged. Sometimes there is a day's error, but it won't make much difference. But it can't be defined accurately in the lunar calendar!

It should be noted that-

In the application of Yi-ology prediction, according to the changes of the 24 solar terms, the division of four seasons, such as spring, summer, autumn and winter, and the alternation of old and new months, is accurately defined!

In the farmer's calendar (lunar calendar), the first day of each month is not the beginning of the month, it is just a sign that is easy to remember or operate. For example, beginning of spring (February 4th or 5th of the Gregorian calendar) is the beginning of a new year and spring. It is generally not considered that the first day of the first month is the first day of the Spring Festival.

The application of the 24 solar terms includes celestial movement and regional climate change law. Therefore, in ancient times, people who knew how to use them were often called astronomical geographers.