If you are a Seinfeld fan, you may already know today marks a special celebration on the show. Festivus has become a way for fans to celebrate the show while carrying its message into real life. Here’s everything you need to know about the fictional holiday.

Festivus was first celebrated in a 1997 episode of ‘Seinfeld’

The holiday appeared in Season 9, Episode 10 titled “The Strike,” which aired on Dec. 18, 1997. 

The character of Frank Costanza, George Costanza’s father on the show, invents the holiday after getting into a fight over a doll with another Christmas shopper. He then decides to plan a holiday to celebrate without the commercial side of the holiday season.

“Out of that, a new holiday was born,” Frank declares on the show, according to History.com. “A Festivus for the rest of us.”

Since then, fans have celebrated the holiday on Dec. 23 in honor of the show.

The rules of Festivus

The fictional holiday features several customs. First, the airing of grievances. After a meal, each person at the table gets the opportunity to speak about how disappointed they are in other people or each other, according to The Providence Journal. A feat of strength is then held after the meal. Someone at the table has to wrestle and pin the host of the party. In the episode, Frank and George wrestle until Frank is pinned.

“It was another kind of way with dealing with something else that was going on at the time: the rebelliousness of the son against the father and the father trying to prove he was still stronger than the son,” Jerry Stiller, who played Frank Costanza, told The New York Times in 2004, according to History.com.

Festivus celebrations also include an aluminum pole instead of a Christmas tree, menorah or other holiday decorations. The pole symbolizes anti-commercialism.

When it comes to the actual meal, fans have accepted spaghetti or meatloaf as the main dish as it was difficult to decipher which one was being served in the scene. The meal was later identified as meatloaf served on a bed of lettuce, according to ABC7. Some fans have featured various foods appearing on the show as part of their celebrations like poppyseed bagels or black and white cookies.

Festivus was inspired by a ‘Seinfield’ writer’s own family tradition

Seinfeld writer Dan O’Keefe was inspired by one of his family’s holiday traditions to create Festivus. He said his father Daniel O’Keefe started a version of the holiday in 1966. It originally occurred to celebrate the anniversary of his first date with his wife but later evolved as their children were born.

“It was entirely more peculiar than on the show,” O’Keefe told The New York Times, per History.com.

The family reportedly aired their grievances into a tape recorder and siblings partook in wrestling matches. O’Keefe added that his father put a clock in a bag and nailed it to a wall, a detail that didn’t make it to the show.