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Significant Reference Date

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As an Easter Egg, writers will sometimes use a Real Life calendar date as an In-Universe reference point.

This could be a reference to a TV episode's original air date or a movie's original release date. Or perhaps a character's birthday, anniversary, etc. matches that of the actor who plays him.

Note: even when this is not Canon, fanon is likely to assume this is true for works set in the period they were filmed in and characters in those works. Fan Fic for that work will be affected accordingly.


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    Anime and Manga 
  • Inverted by the Japanese DVD release of The Disappearance of Haruhi Suzumiya, which was released on December 18, 2010. (December 18 is the date in-story when weird stuff starts happening). Taken even further by Fanon, which believes that the exact date of the "three-years-ago" Tanabata was July 7, 2007, making the exact in-story date of Disappearance December 18, 2010.
  • Dragon Ball: May 9th (5/9) is officially recognized by the Japanese Anniversary Association as "Goku Day", because "five" and "nine" are respectively pronounced "go" and "ku". In-Universe, May 9th is "King Piccolo Day", the day in which Goku's one-time Arch-Enemy successfully took over the world.
  • Two different Gundam characters (Wing's Relena Peacecraft and 00's Setsuna F. Seiei) were born on April 7th, the date the original Mobile Suit Gundam debuted in 1979; for Relena it's doubly significant, since her series premiered on that same date in 1995.
  • The Episode 21 of Mobile Suit Gundam: Iron-Blooded Orphans was aired on National Biscuit Day, when Biscuit Griffon dies.
  • Most of the characters in Neon Genesis Evangelion share birthdays with their voice actors.
  • The original air dates for the Fate/Zero anime hit some ironic dates
  • During the Kanto field trip in Pokémon the Series: Sun & Moon, it's mentioned that the Hau'Oli Pokemon school is celebrating its 20th anniversary... just like the anime itself was.
  • The birth dates of the members of the fictional Raise A Suilen in the BanG Dream! franchise are references to milestone dates in 2018 for the real-life Raise A Suilen, with a single exception all going back to when they were tentatively named The Third:
    • A double one with Layer's birthday of January 13, shared with both her performer Raychell's and with the first day of the GARUPARTY! in Tokyo concert where The Third debuted as a backup band.
    • Pareo's birthday is March 25, on which was held The Third 1st Live.
    • Masking's birthday is May 12, the first day of Bang Dream! 5th Live where The Third was the opening act.
    • Rokka's birthday July 17, the date of The Third 2nd Live which ended with the announcement of the band's new name.
    • Chu2's birthday is December 7, the first day of Bang Dream! 6th Live featuring Raise A Suilen as the main act and where their animated alter egos were first revealed.
  • Love Live! often announces major projects on June 30th, the day the franchise officially started in 2010.
  • Episode 46 of the JoJo's Bizarre Adventure anime adaptation was released on National Donut Day in the United States. Kakyoin is killed by having a hole punched through his abdomen.

    Comic Strips 
  • Garfield's official birthday June 19th, 1978, the day the strip debuted in newspapers across America. An unusual example of Comic-Book Time in that while he does admit he's aged four decades, neither he nor anything else around him make that readily apparent. He's definitely got Creme Puff beat.

    Fan Works 

    Films — Animation 
  • Cars:
  • Turning Red: While bearing no plot impact, May 18, the presumed day of the 4Town concert in Toronto (mistaken for Toledo) is also the day Mount St. Helens erupted in Washington State in 1980. Bear in mind, pun not intended, that the events of this film took place 22 years later and far from the volcano.
  • In UglyDolls, Moxy circles May 10th on her calendar during the song "Today's The Day". This was the original release date of the film before it was moved to avoid competition from Pokémon Detective Pikachu.

    Film — Live-Action 


    Live-Action TV 


  • American Housewife: The episode "Surprise" takes place on Oliver's 13th birthday, and his date of birth is revealed to be January 17, 2004. The episode originally aired on January 17, 2017.
  • Babylon 5: "Z'Ha'Dum", the third season finale, is preceded by two episodes in which a series of ominous captions count down the days until Event Z. The two episodes begin with captions reading, respectively, "Z Minus 14 Days" and "Z Minus 7 Days" — which are also how long the audience had to wait for "Z'Ha'Dum", the episode in which Event Z occurred.
  • The Big Bang Theory:
    • In "The Excelsior Acquisition," Sheldon finds a traffic summons concerning an traffic incident that occurred on 11/16, the airdate of "The Adhesive Duck Deficiency," in which the violation happened.
    • In "The Agreement Dissection" Sheldon lists the offences Leonard committed in the teaser as happening on April 28th, the original air date.
  • Buffy the Vampire Slayer:
    • Buffy identifies herself as a "Capricorn on the cusp of Aquarius." Since her first two birthday episodes, "Surprise" and "Helpless" both aired on January 19th, this is taken to be her actual birthday; this is canonised in the comics.
    • In "Help," Tara's tombstone shows her date of death as May 7, 2002 - the date "Seeing Red", her death episode, aired. Considering this, it's something of an aversion that her shown date of birth, October 16, 1980, doesn't match up with the airdate of her birthday as shown in "Family" (November 7). On the other hand, "Help" itself aired on October 15th, and night passed before the Grave-Marking Scene, making it consistent with a birthday pilgrimage.
    • "Conversations With Dead People" begins with a title card identifying the episode (staggeringly rarely done), followed by the date and time; November 12, 2002 8:01 PM, which on the night it aired was accurate to the minute (the Previously on… took up the 8:00 first minute). The intention was to imply the episode takes place in Real Time, 24-style.
  • Columbo: In episode "Uneasy Lies the Crown" Columbo offhandedly states that he's been on the force 22 years. That episode aired 22 years after the original Columbo pilot movie, "Prescription: Murder".
  • Community:
    • In the Christmas Episode "Abed's Uncontrollable Christmas", Troy says "Today's December 9th"... the same date as the episode's original 2010 air date.
    • Also done in the previous season's Christmas episode. Shirley chastises Jeff for disrespecting the holiest day of the year, to which Jeff responds that it's December 10.
  • Doctor Who:
    • More so in classic serials than the modern run, the year in which an adventure was set was likely to be an exact multiple of years (xty years / x centuries, for example) from the year of original transmission.
    • The 23rd of November, the date of the show's first broadcast, crops up a lot, especially in the Expanded Universe and in Milestone Celebration stories:
      • The 25th anniversary serial "Silver Nemesis" is set on the 23rd of November 1988, the very day its first part was broadcast.
      • And "Remembrance of the Daleks" on 23rd of November 1963 (the Doctor manages to walk out of the room just as the episode was being introduced on TV).
      • Both the modern-day Clara Oswald (in 1986 per "Dark Water") and her Victorian counterpart Clara Oswin Oswald (in 1866 per "The Snowmen") were born on 23 November, over a century apart.
      • The novel Shroud of Sorrow is set on 23rd November 1963.
      • The 50th anniversary audio The Light at the End summons all the Doctors to the 23rd of November, 1963, with a little flashing red light.
      • The 50th anniversary audio The Time Machine is set on 23rd November 2013.
      • The audio 1963: The Space Race is set on 23rd November 1963.
      • In the short story "The Age of Ambition", Victoria Waterfield's mother died on 23rd November 1863.
      • The Sarah Jane Adventures episode "Lost in Time" is set on 23rd November 2010.
      • The K9 episode "The Cambridge Spy" is set on 23rd November 1963.
    • "The Waters of Mars" tried to do this: the story was set on November 21, 2059, but the episode aired on November 15, 2009 due to a scheduling conflict.
    • In Series 5, Amy's wedding and the date from which the cracks in time radiate is revealed in "Flesh and Stone" to happen on June 26, 2010 — the broadcast date of "The Big Bang", the episode in which Amy's wedding takes place.
    • The Doctor's apparent death in "The Impossible Astronaut" happens on April 22, 2011 in Utah, which due to the time zone difference was April 23 (the episode's air date) in the show's domestic United Kingdom.
    • "Resolution" is set on its original airdate of January 1, 2019.
  • In a third season episode of the 60's Dragnet, Sgt Joe Friday reveals his birthday is April 2nd, which is also Jack Webb's birthday.
  • Frasier: The date of the pilot is subtly referenced throughout the series. For example, in the fifth season, Martin says he hasn't seen his brother in five years.
  • In the Grimm episode “Breakfast in Bed”, a translation of writings related to a mysterious stick the group have recently discovered reveals that some significant event is destined to happen on 24 March 2012, which was not only a date in the future, but the date when the series’ penultimate episode (the first of the two-part finale) would air in the real world.
  • I Love Lucy:
    • In "Lucy Gets a Paris Gown", Lucy wants to get a new designer dress while in France. Ricky reads a letter Lucy wrote in Hollywood, promising Ricky if he'd buy her a Hollywood designer dress, she would NEVER ask for another designer dress. The note is dated 2/28/55 — The broadcast date of the episode "The Fashion Show" in which Lucy gets said dress. Extra coolness points awarded when you realize the writers had no idea that anyone in the future would create episode guides, listing airdates.
    • In "Lucy's Mother-in-Law", Lucy tells the assistant of a mind reader that her birthday is August 6th, Lucy's actual birthday.
  • At the end of M*A*S*H episode "Welcome to Korea" (B.J.'s first episode), the PA announces the date that Col. Sherman Potter would arrive to take command of the 4077th. That date was the date of the broadcast of the next episode, in which Potter is introduced.
  • Maverick:
    • In "The Day They Hanged Bret Maverick", Bret's tombstone shows his birthdate to be April 7th (the same as that of James Garner). The death date on the tombstone is September 21st, which was the airdate of this episode.
    • In "The Misfortune Teller", Maverick gives his birthday as May 11th, which was the birthday of Leo Townsend (the writer of that episode).
  • The Middle: In "The Guidance Counselor", guest star Whoopi Goldberg gives her character's birthday as November 13th, same as her own.
  • Mister Rogers' Neighborhood: Prince Tuesday is an invoked day-of-the-week variant; his birth aired on a Tuesday.
  • In Power Rangers RPM, Summer asks if Project Go-Onger was built in 1975, which happens to be the debut year of the Super Sentai franchise from which Power Rangers pulls its fight footage and costumes from.
  • The Outer Limits (1995):
    • In "Joyride", Colonel Theodore Harris' first trip into space took place on September 16, 1963. This was the date that The Outer Limits (1963) pilot "The Galaxy Being" was originally broadcast. Cliff Robertson played the protagonist in both episodes.
    • In "Bodies of Evidence", three crewmembers of the space station Meridian were murdered by the alien entity on June 20, 2037. This episode was broadcast on June 20, 1997.
  • In the Quantum Leap episode "The Leap Back", Al mentions that the day outside the imaging chamber was September 18th, 1999. The episode originally aired September 18th, 1991.
  • In the Remington Steele episode "Elegy in Steele", Steele's arch-enemy, Major Descoine, returns and promises that Steele and Laura Holt would be dead by noon that day. As part of his terror campaign, he sees to it that they stumble across headstones with their names and that day's date on them. That date was the original broadcast date.
  • In the final episode of Seinfeld, the events brought up as evidence against the gang are referenced as happening on the original air dates.
  • Skins has constantly proven a nightmare to track the dating for; each series typically airs from January to March, but covers the academic year from September to July/August. Katie's episode in Series 4 provides a clue, though; the bailiffs read out a court order dated February 17th 2010, the day before the episode's airdate (night passed during the episode, so it adds up), indicating that Skins airs in a stretched-out present with time skips.
  • A screen in the Star Trek: Enterprise episode "In a Mirror, Darkly Part 2" gives James T. Kirk's birthday as March 22, which is William Shatner's birthday.
  • In Supernatural the license plate on the Impala for the first two seasons is KAZ 2Y5, referring to the Winchester's birthplace of Kansas and the year the series started, 2005.
  • Hokuto and Minami from Ultraman Ace were both born on July 7th, Eiji Tsuburaya's birthday.
  • In WandaVision, Agnes states that her wedding date is June 2nd. June 2, 1692, was when the Salem witch trials started, hinting at who she really is.


  • In Neil Cicierega's Mouth Sounds mashup album, the metadata properties for the songs are dated May 4, 1999, which was the release date of Smash Mouth's "All-Star" as a single. This continues with Mouth Silence (in which the tracks are dated May 3, 1999) and Mouth Moods (which dates the tracks on May 5, 1999).

    Video Games 
  • The HD version of Sonic Unleashed has domesticated Egg Fighters in the Eggmanland entrance called "EF-MD1991",note  "EF-DC1998" and "EF-XB2006".
    • The MegaDrive version of Sonic the Hedgehog 2 had a debug cheat accessed by playing tunes 1, 9, 9, 2, 1, 1, 2 and 4 in the Sound Test; this corresponds to the game's worldwide release date. note 
  • The Knights' Academy in The Legend of Zelda: Skyward Sword was celebrating its 25th anniversary when the events of the game happen. Skyward Sword was released celebrating The Legend of Zelda's 25th anniversary.
  • Some of the characters' birthdays in Fire Emblem: Awakening reference the release dates of the earlier games in the series or holidays. Nearly all of the second generation characters' birthdays are the same as the Japanese release dates for most of the games in the series.
  • Hideo Kojima often includes his birthday in his works. Examples include:
  • Kirby Star Allies has a weird example. One particular track, Void's theme, shifts to a 8-bit rendition of said theme in the style of Kirby's Dream Land at around four minutes and twenty-seven seconds, or 4:27, mirroring the release date of said game. Considering that Void is heavily implied to be linked to Kirby (with Dream Land being considered his "origin"), this only hammers in the point, assuming it isn't a coincidence.
  • In Splatoon 2's Rhythm Game Squid Beatz 2, one bonus song that can be unlocked is "Splattack!", the main theme of the original Splatoon. When played on Hard mode, the chart has exactly 528 notes, referencing Splatoon's initial release date of May 28, 2015, or 5/28.
  • To get the Drunk World Easter Egg in Terraria, the world seed used to generate the world must be 05162020: referencing the date May 16th, 2020- the release date of Terraria's 1.4 update.
  • The iDOLM@STER:
    • Teru Tendo of SideM was born on February 23, the pre-registration starting date for his game.
    • Kohaku Okuzora of Starlit Season was born on July 26, the release day of the original arcade version of The iDOLM@STER.

    Western Animation 


  • The Daniel Tiger's Neighborhood episode "Daniel's Fish Dies; Daniel's Strawberry Seeds", a Very Special Episode about death, aired on February 26, 2020, one day before the 17th anniversary of the death of Fred Rogers, the star of the show it was spun off from.
  • Justice League: In "A Better World", Flash has to unlock Lord Batman's restraints on the other Leaguers, which is password-protected. Batman knows that the password is 91939. 1939 is the year the first Batman comic came out.
  • In the pilot episode of The Looney Tunes Show, Bugs Bunny and Daffy Duck's birthdays are stated as being July 27th and April 17th, the dates that their first theatrical shorts were first released.
  • In the first episode of Transformers: Prime, it's established that the Autobots and Decepticons had a brief, but eventful battle three years prior which ended with the Decepticons defeated, Megatron MIA, and Starscream in charge. The episode was aired three years after Transformers 2007 came out in theaters, with a broadly similar premise and ending.
  • On Hey Arnold!, when Rhonda asks Arnold what day his birthday is, he replies "the 7th" - a reference to the series premiere date of October 7, 1996.
  • Coincidentally, both The Powerpuff Girls (1998) and the model era of Thomas & Friends stopped being reran in the Netherlands after May 10, 2015.
  • In "Project B.R.A.I.N.", an episode of Pinky and the Brain which recalls the experiment that led to Pinky and Brain gaining human-like intelligence (and Brain's first attempt at world domination), the dates listed on the time codes for the experiment are September 9 and 10, 1995. Those dates are nods to the show's premiere dates in both Saturday morning and prime time.
  • SpongeBob SquarePants has an episode that was aired on Spongebob's 30th birthday (July 14) called "Pineapple Invasion".
    • SpongeBob's birthday itself is this, as it's the day after the one of his voice actor Tom Kenny.
  • Star Wars: The Clone Wars:
    • In "Shattered", Anakin's password is 8108; 8/10/08 (Aug. 10, 2008) is the release date of the pilot movie.
    • "Shattered", which takes place at the same time as Revenge of the Sith, aired on May 1st, 2020. This is a reference to the 501st Legion via M/D/Y formatting (5/01/2020), but taking this to mean Order 66 happens on this day also means that about three days later, on May 4th — otherwise known as Star Wars Day, Luke and Leia are born.
    • The clone cadet unit that Boba infiltrates is the 322nd Unit. There's also the similarly numbered 332nd Company that joins Ahsoka in the Siege of Mandalore. 3/22 is the date A New Hope started filming in 1976.