The Cowherd and the Weaver Girl is a Chinese folk tale. The tale of the cowherd and the weaver girl is a love story between Zhinü (織女; the weaver girl, symbolizing the star Vega) and Niulang (牛郎; the cowherd, symbolizing the star Altair). Their love was not allowed, thus they were banished to opposite sides of the heavenly river (symbolizing the Milky Way). Once a year, on the 7th day of the 7th lunar month, a flock of magpies would form a bridge to reunite the lovers for one day. There are many variations of the story. The earliest-known reference to this famous myth dates back to over 2600 years ago, which was told in a poem from the Classic of Poetry. The tale of the Cowherd and the Weaver Girl has been celebrated in the Qixi Festival in China since the Han dynasty. It has also been celebrated in the Tanabata festival in Japan, and in the Chilseok festival in Korea. The story was selected as one of China's Four Great Folktales by the "Folklore Movement" in the 1920s—the others being the Legend of the White Snake, Lady Meng Jiang, and Liang Shanbo and Zhu Yingtai—but Idema (2012) also notes that this term neglects the variations and therefore diversity of the tales, as only a single version was taken as the true version.