Festivus is a holiday celebrated on the 23rd of December, and is commonly celebrated as a protest of the consumerist and greedy MegaChristmas
Festivus is a reference to a 1997 episode of Seinfeld, titled "The Strike." This episode features George Costanza (who is referenced in VA-11 Hall-A through Art, the private detective) and his family celebrating Festivus. The traditions include erecting an undercoated aluminum pole instead of a Christmas tree, Airing of Grievances, in which everyone speaks out about who/what has disappointed them in the past year, and Feats of Strength, which requires the head of the household to select one person to challenge to a wrestling match. Festivus is not over until the head of the household is pinned. None of these traditions are referenced in the game.