The Mid-Autumn Festival, also known as the Moon Festival, is celebrated in Yulin, China, on the 15th day of the 8th lunar month. This traditional festival typically falls in September or October, depending on the lunar calendar. The exact date varies each year, but it is always on the same day of the lunar calendar.

The Mid-Autumn Festival is a time for family reunions, moon gazing, and enjoying mooncakes, a traditional Chinese pastry. It is believed that the moon is at its roundest and brightest on this day, symbolizing completeness and harmony. The festival has its roots in ancient Chinese mythology and is celebrated across various ethnic groups in China.

The timing of the Mid-Autumn Festival is significant for several reasons. Firstly, it is a time when the weather is generally cooler, making it more comfortable for outdoor activities such as moon gazing. Secondly, the festival coincides with the autumn harvest, a time when farmers are reaping their crops and celebrating the bountiful yield. This agricultural connection is reflected in the traditional customs and foods associated with the festival.

According to the Chinese lunar calendar, the Mid-Autumn Festival is always on the 15th day of the 8th lunar month. The lunar calendar is based on the phases of the moon and is approximately 13 days shorter than the Gregorian calendar. This means that the Mid-Autumn Festival can fall on any date between September 8th and October 8th in the Gregorian calendar.

Data from the Chinese Ministry of Culture indicates that the Mid-Autumn Festival is one of the most important traditional festivals in China, with a history of over 3,000 years. It is celebrated not only in Yulin but also in other parts of China and among Chinese communities worldwide. The festival is recognized by UNESCO as part of the Intangible Cultural Heritage of Humanity, highlighting its cultural significance.

In conclusion, the Mid-Autumn Festival in Yulin is celebrated on the 15th day of the 8th lunar month, typically in September or October. This timing is significant due to the cooler weather, the autumn harvest, and the festival's deep historical and cultural roots.