Qixi Festival is the most romantic of traditional Chinese festivals, and also known as a Chinese Valentine's Day. It's based on a romantic legend about a weaver girl and an ox herd.
The festival has been celebrated since the Han Dynasty (206 BC – 220 AD). On May 20, 2015, the Qixi Festival was added to the National Intangible Cultural Heritage list by the State Council of China.
It falls on the 7th day of the 7th Chinese lunar month. In 2019 that's August 7 (Wednesday).