What is the nickname of Mid-Autumn Festival? What is the origin?

There is no nickname for solar terms in beginning of autumn, and its origin is as follows:

In ancient times, beginning of autumn was divided into three periods: "the cool breeze first arrived". After beginning of autumn, the north wind began to blow in many areas of China, and the south wind gradually weakened. The small north wind brings coolness to people. "The white dew falls at the second hour", because the sun is still strong during the day, and the cool breeze blows at night to form a certain temperature difference between day and night. In the morning, the water vapor in the air condenses into crystal dew and falls on outdoor plants. "Three-time chilling cicada", the cicada at this time, with plenty of food and suitable temperature, sings proudly on the branches blown by the breeze, as if to tell people that the hot summer has passed. After waiting for 5 days, beginning of autumn 15 days, it gradually got cold. Cooling is a climate trend. According to beginning of autumn Sanhou's description, this may happen when the climate is cold.

Beginning of autumn solar terms indicate that hot summer is coming and autumn is coming. When beginning of autumn arrived, many parts of our country were still in hot summer. After beginning of autumn, although the summer heat is hard to disappear for a while, there is still the afterglow of "autumn tiger", but the general trend of the weather is getting colder and colder. The temperature difference between morning and evening is gradually obvious, which is often very hot during the day and relatively cool at night. Of course, due to the different climates in different parts of the country, the real start time of autumn is also inconsistent.

Beginning of autumn, one of 24 solar terms, is beginning of autumn when the sun reaches 135 degrees on August 7th or 8th every year. Beginning of autumn is the thirteenth of the twenty-four solar terms, and it is the solar term that begins in autumn. After beginning of autumn (solar term), the next rain will cool down after autumn, so there is a saying that "an autumn rain will bring a cold". As early as the Zhou Dynasty, on the day of beginning of autumn, Emperor Tiandi personally led the princes and doctors of the Three Kingdoms and Nine Counties to the western suburbs to welcome autumn and hold a sacrificial ceremony.