August 15th, August 7th. August Festival refers to one of the two traditional festivals in China, namely Mid-Autumn Festival and Chinese Valentine's Day. The Mid-Autumn Festival falls on the 15th day of the eighth lunar month, while in Chinese Valentine's Day it falls on the 7th day of the eighth lunar month. The dates will be different in the Gregorian calendar years, because the lunar calendar and the Gregorian calendar do not correspond completely.