The date is known to social media and movie fans around the world as "Mean Girls Day."
Here's the backstory: In the popular 2004 film there's scene where Aaron Samuels (portrayed by Jonathan Bennett) turns to Cady Heron (played by Lindsay Lohan) in class and asks her what day it is.
"It's October 3," she answers.
Since then, October 3 has joined other dates made significant by films.
So how should you celebrate it?
Glad you asked:
Try and score some tickets to the "Mean Girls" musical
"30 Rock" funny woman Tina Fey wrote the film and is now blessing the world with a musical version, which is premiering for a five-week run at Washington's National Theater on October 31 and later heading to Broadway.
Naturally, the tickets go on sale Tuesday.
If you are in New York on October 3, there is a planned celebration at the August Wilson Theatre featuring cheese fries from Sweetery's.
Eat cheese fries or Taco Bell
Because, see above.
Who can forget the character Regina George's classic line, "Whatever, I'm getting cheese fries."
Or her assertion that she couldn't eat Taco Bell as she was on an "all carb diet."
Try and make "fetch' happen
Speaking of Regina George, she was so right when she said fetch isn't going to happen. But you can still try and give the slang word some love by using it.
Visit the stars GoFundMe page
Bennett tweeted a video on Tuesday, featuring his fellow "Mean Girls" stars Amanda Seyfried, Lacey Chabert and Daniel Franzese and asking fans to donate money for the victims of the Las Vegas shooting.
"We want to turn the attention to those who need it," Bennett said before asking fans to give $3 in honor of October 3rd.
All donations to the "Mean Girls for Las Vegas" GoFundme page
will go to the National Compassion Fund to aid those affected by Monday's massacre.
"Guys look we know 'fetch' is never going to happen but we can make this happen," Chabert said.
Go follow Lindsay Lohan on social media
It's ok to admit that you are still a little obsessed with the red-headed starlet who went from ingenue to inmate at one point.
Lohan still has love for the movie that helped make her a star. Just a few days ago, she shared an Instagram story of herself re-watching "Mean Girls" to the thrill of her followers.
The actress told CNN last year during a Facebook Live
interview that she's "been trying so hard to do a 'Mean Girls 2.' It is not in my hands."
"I know Tina Fey and Lorne Michaels and all of Paramount are very busy," Lohan said. "But I will keep forcing it and pushing it on them until we do it."
Watch the movie
Take a page from Lohan and watch "Mean Girls" in honor of "Mean Girls Day."
And don't forget that on Wednesdays we wear pink.