Qingming, literally meaning "clear and bright," is known in China as the tomb-sweeping day, but its origins lie in the solar terms and suggests a change of climate.

Qingming usually occurs on April 4 or April 5 when the sun's elliptical longitude reaches 15 degrees, marking a noticeable warm weather and rich food sources.

This year, it falls on April 5.

The arrival of Qingming signals the end of the "three periods of waiting" – waiting for the tung flower to blossom, waiting for the field mouse to go back to the caves, and waiting for the rainbows to show up in the sky.

Qingtuan (green sticky rice balls with sweet fillings) are popular in the regions south of the Yangtze River including Shanghai.

Sticky rice flour are dyed with grounded wild vegetable juice, and then shaped into balls. Sweet bean paste mixed with lard is the most common filling, but there are also creative fillings depending on local tastes. Check out the video.