Festivus is both a parody and a secular holiday celebrated on December 23rd
Festivus serves as an alternative to participating in the pressures and commercialism of the Christmas season. Originally a family tradition of Seinfeld scriptwriter Dan OKeefe – Festivus entered popular culture after it was made the focus of the 1997 Seinfeld episode The Strike.
Festivus is a non-commercial holiday’s celebration but it includes a Festivus dinner, an unadorned aluminum Festivus pole, practices such as the “Airing of Grievances” and the labeling of easily explainable events as “Festivus miracles”.
Source: Wikipedia