Forgotten Birthday. This can combine with Scary Surprise Party for extra comedy value. Related to Ironic Birthday, which is when the character doesn't want to celebrate despite the fact it's their birthday. Compare with Birthday Hater for when it is their birthday, but they don't want to celebrate it anyway.
- In the Steven Spielberg film Always, Pete (Richard Dreyfuss) throws a big shindig for Dorinda (Holly Hunter)'s birthday... except it wasn't her birthday. He keeps saying he remembered it, she keeps saying yeah, but he remembered it wrong.
- This is a plot point in Declare: history thinks Kim Philby was born on January 1 but in the book, his real birthday is on December 31, which he hides from everyone because he is functionally invulnerable on all days except his birthday.
- Garrett, P.I.: In Whispering Nickel Idols, Mafia Princess Belinda throws a 60th birthday party for her father Chodo, even though it's not the right day or the right year for it. Everyone she invites already knows this, but come anyway because they realize the party is just a front for a major criminal summit.
- In It's Always Sunny in Philadelphia, the gang plans out a surprise birthday for Charlie to make him feel better. But it isn't his birthday. Frank just said that to trick them into planning a luau party for his own birthday.
- M*A*S*H: In order to brighten the mood of the camp BJ tells everyone it's Hawkeye's birthday and they arrange a Surprise Party for him. Hawkeye 'accidentally" lets slip that the same day is also BJ's wedding anniversary. Ultimately Hawkeye has to go out on a medical emergency so BJ recruits some miscellanous extra to say it's his birthday.
- Inverted in the Seinfeld episode, "The Outing", where George, Kramer, and Elaine each plan on getting Jerry something special for his birthday; Kramer is the first to give Jerry his present, though Jerry insists it's not his birthday, although the others insist that it is, to which Jerry comments, "Maybe you're right, maybe it is my birthday..."
- WWE: In one part of the memorable "This Is Your Life" segment on Raw, Mankind brought a clown to sing "happy birthday" to The Rock as well as bringing out a birthday cake for him. Because he was absolutely unimpressed, this is what he has to say to Mankind:
The Rock: "The Rock's birthday is May 2, you stupid son of a bitch!"
- Played for Drama in Next To Normal when the ill Diana bakes her son a cake during the song "It's Gonna Be Good"... only for the audience to discover Gabe's been dead for nearly a decade and a half.
- In one pictures for sad children comic, a guy receives a surprise birthday party on the day before his birthday, then on his actual birthday, then on the day after, then on the day after that...
- Played with in Alice in Wonderland. Alice comes upon the Mad Hatter, the March Hare, and the Doormouse celebrating what she thinks is a birthday party, but they're celebrating their unbirthday - which is any day that isn't your birthday. Alice realizes it's her unbirthday too and they include her in the celebration.
- An episode of Fish Hooks had the entire class thinking it was Clamantha's birthday, even though it wasn't.
- On Foster's Home for Imaginary Friends, Bloo kept throwing surprise birthday parties for Mac on any day other than his birthday.
- In one Phineas and Ferb episode, Monogram and Carl surprise Perry with a birthday party when he enters his secret lair. Perry's silent stare tells them it's not his birthday. Becomes a Call Back joke later when Perry arrives at Doofenshmirtz's place. Doof mentions he got an invitation to the party but didn't go because he suspected it was a trap.
- In the beginning of the Spongebob Squarepants episode "Opposite Day", Spongebob and Patrick are annoying Squidward by throwing a birthday party for him, which it isn't as the quote from above states it. This is what prompts him to moving out of Bikini Bottom, which apparently backfired on him thanks to Spongebob and Patrick.
- For some reason, Jason Statham's birthday keeps getting referred to as the 12th of September, even though it's actually in July. He usually politely thanks people for the birthday wishes, but also points out it's not his birthday.
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