August 15th of the lunar calendar is the traditional Mid-Autumn Festival. This is the middle of autumn, so it is called Mid-Autumn Festival. In China's lunar calendar, a year is divided into four seasons, and each season is divided into three parts: Meng, Zhong and Ji, so Mid-Autumn Festival is also called Mid-Autumn Festival. The moon on August 15th is rounder and brighter than the full moons in other months, so it is also called "Moon Night" and "August Festival". On this night, people look up at the bright moon in the sky like jade, and naturally look forward to family reunion. Wanderers who are far away from home also take this opportunity to pin their thoughts on their hometown and relatives. Therefore, Mid-Autumn Festival is also called "Reunion Festival".

Mid-Autumn Festival, also known as Moon Festival, Autumn Festival, Mid-Autumn Festival, August Festival, Moon Chasing Festival, Moon Playing Festival, Moon Worship Festival, Daughter's Day or Reunion Festival, is a traditional cultural festival popular in many ethnic groups in China and countries in the cultural circle of Chinese characters, which falls on August 15th of the lunar calendar. Because it is just half the value of Sanqiu, hence the name, some places set the Mid-Autumn Festival on August 16th.

Extended data:

According to China's calendar, the eighth month of the lunar calendar is in the middle of autumn, which is the second month of autumn, and it is called "Mid-Autumn Festival", while the fifteenth day of August is in the middle of it, so it is called "Mid-Autumn Festival".

There are many nicknames for Mid-Autumn Festival: it is called "August Festival" and "August and a half" because it falls on August 15th; Because the main activities of Mid-Autumn Festival are all around the "moon", it is also commonly known as "Moon Festival" and "Moon Festival". The full moon in Mid-Autumn Festival symbolizes reunion, so it is also called "Reunion Festival". In the Tang Dynasty, Mid-Autumn Festival was also called "Correcting the Moon".

The record of "Reunion Festival" was first seen in the Ming Dynasty. "Notes on the Tour of the West Lake" said: "August 15th is the Mid-Autumn Festival, and people send mooncakes as a token of reunion". "A Brief Introduction to the Scenery of Dijing" also said: "On the 15th of August, when the moon is sacrificed, the cakes will be round, the melons will be wrongly divided, and the petals will be carved like lotus flowers. ..... Those who are married to mothering will return to their husband's house one day, which is called the Reunion Festival ".

References:

Baidu Encyclopedia-Mid-Autumn Festival