The Mid-Autumn Festival will be celebrated on September 29, 2023, according to the Chinese lunar calendar. This date is determined by the specific phase of the moon, which varies each year. Xiangyang No.4 High School, like many educational institutions in China, typically follows the traditional calendar for celebrating festivals.

The Mid-Autumn Festival is a significant cultural and historical event in China, celebrated to honor the moon's fullness and the gathering of family. It is traditionally marked by moon-viewing, eating mooncakes, and lighting lanterns. The festival's date is based on the lunar calendar, which is about 13 days shorter than the Gregorian calendar used in the United States. As a result, the Mid-Autumn Festival falls on a different date each year, usually in September or October.

The Chinese lunar calendar is a lunisolar calendar, meaning it is based on the cycles of the moon and the solar year. The year is divided into 12 months, each of which is approximately 29.5 days long, and an extra month is added in some years to align with the solar year. This calendar is used to determine the dates of various traditional festivals, including the Mid-Autumn Festival.

According to the Chinese Ministry of Education, schools are encouraged to promote traditional culture and festivals as part of their curriculum. Xiangyang No.4 High School, as an educational institution, likely follows this guidance and celebrates the Mid-Autumn Festival to educate students about Chinese culture and history. The festival's celebration at the school may include cultural activities, such as mooncake-making workshops, lantern displays, and lectures on the festival's significance.

In conclusion, the Mid-Autumn Festival will be celebrated on September 29, 2023, at Xiangyang No.4 High School, following the traditional Chinese lunar calendar. This festival is an important cultural event that reflects the rich heritage of China and is celebrated to foster a sense of community and cultural identity among students.