via About.com:
The Moon festival (also called the Mooncake or Mid-Autumn festival) falls on October 6 in the year 2006. What is the Moon festival? Every year on the fifteenth day of the eighth month of the lunar calendar, when the moon is at its maximum brightness for the entire year, the Chinese celebrate "zhong qiu jie." Children are told the story of the moon fairy living in a crystal palace, who comes out to dance on the moon's shadowed surface.
Today, Chinese people celebrate the Mid-Autumn festival with dances, feasting and moon gazing. Not to mention mooncakes. While baked goods are a common feature at most Chinese celebrations, mooncakes are inextricably linked with the Moon festival. One traditional mooncake is filled with lotus seed paste and quite distinctive in appearance (see top photo). Roughly the size of a human palm, these mooncakes are quite filling, meant to be cut diagonally in quarters and passed around.

