A festival or fest is an event, usually staged by a local community, which centers on some theme, sometimes on some unique aspect of the community. "Cherry Days" in Paonia, Colorado is a typical festival.
When used as in the meaning of a festival, feast is thought of as a religious festival rather than a film or art festival.
Seasonalfestivals are determined by the solar and the lunar calendars and by the cycle of the seasons.
A recognized winter festival, the Chinese New Year, is set by the lunar calendar, and celebrated from the day of the second new moon after the winter solstice.