The TV show SEINFELD was so popular, many of the words and phrases have become widely known in pop culture.
"Festivus," apparently celebrated by one of the show's writers when he was a kid, is: "both a parody and a secular holiday celebrated on December 23rd that serves as an alternative to participating in the pressures and commercialism of the Christmas season. It has been described as "the perfect secular theme for an all-inclusive December gathering". (Wiki)
Let the airing of grievances begin.