The moon on August 15 is rounder and brighter than the full moon in other months, so it is also called "moonlit night" and "August Festival". On this night, people look up at the bright moon like jade in the sky and naturally look forward to family reunion. Wanderers who are far away from home also take this opportunity to pin their thoughts on their relatives in their hometown. Therefore, Mid-Autumn Festival is also called "Reunion Festival".
There are many stories about the origin of Mid-Autumn Festival. The word Mid-Autumn Festival first appeared in Zhou Li. The Book of Rites and the Moon Order said: "The Mid-Autumn Festival moon nourishes aging and follows the porridge diet."
One theory originated from the sacrificial activities of ancient emperors. It is recorded in the Book of Rites that "the sun rises in spring and the moon sets in autumn", and the moon is a sacrifice to the moon, indicating that as early as the Spring and Autumn Period, emperors began to offer sacrifices to the moon and Yue Bai. Later, aristocratic officials and scholars followed suit and gradually spread to the people.
Second, the origin of Mid-Autumn Festival is related to agricultural production. Autumn is the harvest season. The word "autumn" is interpreted as "autumn when crops are ripe" In the Mid-Autumn Festival in August, crops and various fruits are maturing one after another. In order to celebrate the harvest and express their joy, farmers regard the Mid-Autumn Festival as a festival. "Mid-Autumn Festival" means the middle of autumn. August in the lunar calendar is a month in autumn, and the 15th is a day in this month. Therefore, the Mid-Autumn Festival may be a custom passed down from the ancient Autumn Newspaper.
References:
Baidu Encyclopedia-Mid-Autumn Festival