Shangsi Festival, also known as the Double Third Day, is celebrated by the Zhuang ethnic group on the third day of the third lunar month, which falls on April 9 this year.

There are many different theories about the festival's true origins, some say that it stems from a dinner party held on the banks of the Qushui River during the Zhou Dynasty (1100 - 221 BC). Others say it comes from the custom of getting rid of evils by bathing in the river. On this day, people would hold a sacrificing ceremony by the riverside to honor their ancestors, and then bathe in the river with herbs to cleanse and purify their bodies. Following that, young men and women would go for a spring outing – these scenes were described in the ancient text, Shi Jing (The Book of Songs).

Shangsi Festival activities have changed with the times. The entertainment feast and praying for descendants by the river were added in the Han Dynasty (206 BC - AD 220). It was after the Wei and Jin dynasties (AD 220 - 420) that the event developed into the Double Third Day that is fixed on the third day of the third lunar month.

The calligrapher Wang Xizhi from the Eastern Jin Dynasty (AD 317 - 420) wrote in his preface of the Collection of Lanting Poems about how literary men took a bath and composed poetry while drinking from cups left adrift and bobbing along the winding river.

In the Tang Dynasty (AD 618 - 907), it is said the emperor would treat his followers beside the river along with ordinary people enjoying their drink and sight-seeing. People in the Chang'an area would also watch cricket-fighting.

After the Ming and Qing dynasties (AD 1368 - 1911), the ritual activities were gradually omitted, and the festival developed into a spring outing featuring lively activities like drifting cups, drifting eggs, drifting dates, stone throwing, wearing willow-wreaths, hiking and eating glutinous rice and listening to choir music.

As the Shangsi Festival happens so close to the Qingming Festival, many young people today only know about the latter.

The Shangsi Festival is also a day that is considered to be the possible birthday of the Yellow Emperor.