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Pop Culture Holiday

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"Do you know why so many hurricanes hit Miami? [...] Because back on November 5th, 1991, mayor Xavier Suarez proved that if you don't keep the mayor busy with catastrophic disasters, he runs around declaring holidays about video game systems."

Fans will seize any opportunity to celebrate their favorite work, so if there's a reason to associate the work with a certain date, they'll often try to make an unofficial (and sometimes official) holiday out of it.

Common reasons a particular date may be significant to the fandom:

  • It's the date of a Fictional Holiday invented by the work, and fans have made that holiday real. In some cases, the holiday may not have a canon date, and the fandom just deduced when the most logical date would be.
  • It's the anniversary of the work's release.
  • It's the anniversary of an important event in the work's lore.
  • It resembles an Arc Number or other significant number in the story. In Japanese fandom, this can overlap with Goroawase Number.
  • It's the birthday of a character or the work's creator.
  • It's the anniversary of a character or creator's death, leading to more somber memorials as opposed to joyous celebrations.
  • It's a Pun on the work's title or a name or phrase from the work.
  • The work mentioned the date at some point in the story, and as such the date has become a meme.

Celebration can occur at several levels. Some fans may simply gush about the holiday on social media and enjoy the work on their own time, some will put out crafts and fanart, and others will wear themed cosplay and attend holiday meetups to party with other fans. Official marketing for the franchise will certainly celebrate as well, possibly by releasing new content on the day. If the holiday gets big enough, the holiday may become a nationwide or even worldwide celebration that even people not seriously familiar with the work may celebrate the holiday anyway. Some cities have even officiated certain pop culture holidays.

When the same date holds significance for multiple works, expect crossovers between Friendly Fandoms celebrating together.note  Unfortunately, this also means that some Pop Culture Holidays have shared dates with tragedies, such as September 11, which may result in the said Pop Culture Holiday canceled temporarily or permanently, or moved to a different date relevant in the story, if the tragedy overshadows the work.

Compare Significant Reference Date and Milestone Celebration.


    open/close all folders 

    Anime & Manga 
  • August 1st is celebrated as Yaoi Day in Boys' Love fandom circles, as the numbers 8, 0, and 1 correspond to ya-o-i in Goroawase Number interpretations.
  • December 15th was declared the "Otaku Day" in Japan for this subculture, tradition that was expanded to the rest of the world as a kind of "Anime Day." Also, in United States was stated a real "Anime Day" on April 15th.
  • The day the DigiDestined first travel to the Digital World in Digimon Adventure is August 1. The fandom hails that day, therefore, as "DigiDay", or "Odaiba Memorial Day".
  • In 2015, the Japan Anniversary Association declared May 9 to be "Goku Day" because the numbers 5 and 9 can be pronounced as "go" and "ku," respectively, in Japanese. Coincidentally, in the Dragon Ball manga, that day was Piccolo Day, in which the Demon King Piccolo would choose a lottery for a city to be destroyed on the anniversary of his coup d'état against the King of the World.
  • Fullmetal Alchemist fans celebrate October 3rd as the anniversary of the day the Elric brothers burned down their childhood home. It is memorable because "Don't forget 3.Oct.10" is carved into Edward's pocket watch.
  • Gundam:
    • Gundam Day is celebrated on July 8, coinciding with the model number of the franchise's first Gundam, the RX-78-2.
      • There is also Nu Gundam Day, which is celebrated on September 3, coinciding with the model number (RX-93) of its namesake Gundam, which is also a distant successor of the RX-78-2. Adding to that is both Gundams are piloted by Amuro Ray, the first protagonist of the franchise.
    • Zaku day, a day celebrating the titular mech line, is observed on March 9 due to the Goroawase Number reading of 3/9, or za (san)-ku. This day is often celebrated in tandem with Miku Day.
  • September 15th is Ash Ketchum Day, which celebrated the day that Ash won the Alola League and finally broke his over 20 year losing streak. In 2020, it was recognized by The Pokémon Company and both of Ash's English voice actresses, Veronica Taylor and Sarah Natochenny.
  • Pretty Cure fans celebrate Precure Day on February 1st, the day that the first episode of Futari wa Pretty Cure aired.
  • The Prince of Tennis has August 14, celebrating the end of summer and the annual release of the results from the franchise's ever popular "Happy Summer Valentine" event (in which fans are encouraged to vote for their favorite character with the amount of Valentine's chocolate each character receives). The day was so designated, officially, because the event became too big to ignore.
  • Some fans of Osomatsu-kun and Osomatsu-san celebrate March 18th as Iyami Day since 183 is his Goroawase Number.
  • Sailor Moon fans celebrate Usagi's birthday on June 30th.

    Comic Books 
  • Batman Day is a day to celebrate Batman, with the first celebration taking place on July 23, 2014 and subsequent ones on the third Saturday in September. This is officially recognized by DC Comics.
  • Spider-Man Day is August 1st, widely believed to be the character's first appearance in August 1962's Amazing Fantasy #15 (though the comic might have actually released later that month).
  • October 1st for The Umbrella Academy- it's the shared birthday of all seven main characters.

    Films — Animated 

    Films — Live-Action 
  • April 26th is National Alien Day after planet LV-426, where the Xenomorph species was first discovered.
  • October 21st, 2015 was "Back to the Future Day," celebrating the day Marty, Doc Brown, and Jennifer traveled to forward in time to that day in Back to the Future Part II. Many companies acknowledged the holiday by recreating aspects of the film's version of 2015, such as USA Today, which published a front page identical to the one in the movie, Pepsi making "Pepsi Perfect" bottles available and Universal Studios, who made a fictional trailer for the Jaws 19 film shown in the movie. In years besides 2015, October 21st is still acknowledged as "Back To The Future Day" on a much smaller scale. Another date associated with the film series is November 12th, the date in 1955 in which lightning struck the clock tower and the only date to appear in all three movies. Other contenders include October 26th, the date in 1985 where Doc conducted the first time travel, and November 5th, the date in 1955 where Doc came up with the idea for time travel and that Marty traveled back to.
  • The Big Lebowski: March 6th is "The Day of the Dude" according to the Dudeism philosophy/religion inspired by the film's character of "The Dude", as the film was released on March 6, 1998. It is dedicated to relaxation, and one can celebrate by watching The Big Lebowski, drinking white Russians, bowling, or simply "takin' er easy."
  • March 24th is The Breakfast Club Day, as the fateful detention took place on Saturday, March 24th, 1984.
  • Elf: December 18th is "Answer The Telephone Like Buddy the Elf Day." On this day, pick up the telephone and say, "[Your name] the Elf, what's your favorite color."
  • April 8 is Rex Manning Day for Empire Records fans: The movie takes place entirely over the course of one day, April 8th, in which fictional musician Rex Manning is scheduled to sign autographs at the title record store.
  • Naturally, any actual Friday the 13th that rolls around is a time of celebration for Friday the 13th fans, especially if its during the summer months (as those are when the movies are set) or in October. For fan artists in particular it's become something of a "Draw Jason Day", in either the scariest or goofiest ways imaginable.
  • June 8th is Ghostbusters Day, as the first film was released on June 8th, 1984.
  • November 3rd is Godzilla Day, as the anniversary of the first film’s release.
    • July 30th is Mothra’s Day, as the anniversary of her debut film’s release.
  • May 11th is GoodFellas Day, in honor of Henry Hill's terrible no good day that ends in his arrest.note 
  • For obvious reasons, Groundhog Day on February 2nd is a day to celebrate Groundhog Day. Some channels spend the entire day playing the movie (appropriately) on loop. Many people have more interest in the film than the actual holiday.
  • October 3rd is Mean Girls Day, named after a gag when a lovestruck Cady reminisces about October 3rd, when Aaron asked her what day it was. The Broadway musical even offered a discount to audience members who came to the show on October 3rd. Double points for years when October 3rd falls on a Wednesday, where fans are guaranteed to wear pink.
  • Miss Congeniality fans celebrate April 25th, from a gag where Cheryl gives April 25th as an example of her "perfect date." Even William Shatner, who played the pageant MC who asked Cheryl the question, celebrated the holiday on Twitter.
  • Star Wars:
    • May 4 is commonly known as "Star Wars Day" due to the pun "May the Fourth be with you" (as in, "May the Force be with you"). May 5th and May 6th are sometimes celebrated as "Revenge of the Fifth/Sixth" to celebrate Sith Lords and other villainous characters from the franchise.
    • In Los Angeles, May 25th, the release date of A New Hope, is instead the official "Star Wars Day."
    • May 1 is "501st Day", in honor of the 501st Legion, a fan-based costuming organization.
    • Life Day is usually celebrated on November 17, the anniversary of the airing of The Star Wars Holiday Special where Life Day was introduced.
  • James Bond fans celebrate October 5th as "James Bond Day", because that was the date the very first Bond film, Dr. No, had been released in 1962.
  • Tremors fans celebrate April 14th, the day before Tax Day, as "Burt Gummer Day", after the series' protagonist (who notably refuses to pay taxes).
  • Pacific Rim fans celebrate:
    • July 12th, the anniversary of the film’s release.
    • August 10th as K-Day, the anniversary of the first kaiju attack In-Universe.
    • January 12th as the date of the end of the Kaiju War In-Universe. January 12th, 2025, is the specific date, and a Tumblr account countdown to it exists.

  • Alice's Adventures in Wonderland: October 6th is National Mad Hatter Day, inspired by the "10/6" tag on the Mad Hatter's hat in many illustrations. It encourages people to celebrate Alice in Wonderland and act as mad as the Hatter himself, preferably while wearing a top hat.
  • In Italy, March 25th has been established as "Dantedì" (Dante Day), in honour of Dante Alighieri, its most influential national poet. The date corresponds to the one in which Dante's journey through hell is assumed to begin.
  • "The Glorious 25 of May", celebrated as a tribute to Terry Pratchett and People's Revolution from Night Watch Discworld. To celebrate it, fans carry (or wear) lilac flowers. Some fans of both Pratchett and Douglas Adams even combine it with "Towel Day", which is on the same day, carrying towels with lilac flowers embroidered on them.
  • Harry Potter:
    • September 1 is the first day of term at Hogwarts, so it's a date of much significance in the fandom, leading many to celebrate with rereads of the books, rewatches of the movies, fanart, and the like.
    • To a lesser extent, July 31 is Harry's birthday, and as such is often acknowledged and celebrated by fans. It happens to be J. K. Rowling's birthday as well.
    • Britain’s Prime Minister David Cameron declared May 2 as International Harry Potter Day in 2012, which the fandom already observed for the day the Battle of Hogwarts took place in Harry Potter and the Deathly Hallows.
  • Les Misérables: June 5 is Barricade Day, because it is the first day of the historical 1832 June rebellion, which is fictionalized in the book (and musical). It is usually celebrated by creating fan works.
  • Looking for Alaska: January 10th is "Alaska Young Day," referencing the day that the titular Alaska passed away. Fans post images of white flowers since Alaska wore white flowers in her hair when she was younger.
  • Fans of The Lord of the Rings celebrate September 22nd as "Hobbit Day", since that's the birthday of Bilbo and Frodo Baggins.
  • March 2nd is Dr. Seuss's birthday, a day to not just celebrate the esteemed children's author but to encourage reading in general. Teachers across America read Dr. Seuss books to their classes and provide Seuss-themed activities. This often involves wearing tall red-and-white-striped hats.
  • June 16 is the day James Joyce's Ulysses takes place, so the novel and Joyce are commemorated on that day, called Bloomsday, after the protagonist Leopold Bloom.
  • Edgar Allan Poe's birthday on January 19 became the date for a curious ritual in which a mysterious masked individual, dubbed the "Poe Toaster", would appear at Poe's graveside and sip a glass of cognac, leaving three roses in a distinctive pattern. Fans and locals would also gather at the grave to commemorate the author and observe the Toaster. The yearly visits continued for 75 years until 2009, the 200th anniversary of Poe's birth. The Toaster's identity was never confirmed.

    Live-Action TV 
  • Blake's 7 fans mourn on December 21st for "Gauda Prime Day", the anniversary of the broadcast of the show's notorious "Everybody Dies" Ending final episode. (Gauda Prime being the planet the massacre went down on.)
  • Geri Reischl, who replaced Eve Plumb as Jan Brady in The Brady Bunch Variety Hour, is celebrated on January 2 (because she's Jan #2).
  • Brooklyn Nine-Nine fans celebrate September 9th (9/9) as "Nine-Nine Day", for the titular squad.
  • Fans of The Cry of Mann like to celebrate the work's Fictional Holiday "Trool Day" on November 2nd, the day of the series finale. A common activity is to bake lemon muffins, something mentioned in the show repeatedly as a Trool Day activity.
  • Fans of Doctor Who have a few days they celebrate, such as "Black Spot Day" on May 7th (the date on which "The Curse of the Black Spot" takes place in-universe), "Silence Day" on April 23rd (in which Whovians are encouraged to draw tally marks on their skin), TARDIS Day on November 23rd (the anniversary of the show's release), and Dalek Remembrance Day on December 21st (the day on which the Daleks first appeared back in 1963).
    • Another date celebrated in the Doctor Who fandom is March 26th, the date the series came back in 2005 after more than a decade of being cancelled, becoming the "New Who Day" for some fans.
  • September 11, 1997 was celebrated with a big rally in Seattle as "Frasier Crane Day" for the series' 1000th episode. Nowadays that date isn't celebrated as a festive occasion for obvious reasons. Harsher in Hindsight when you realize that co-creator David Angell and his wife Lynn were two of the dead who were aboard one of the flights.
  • October 15th is "National I Love Lucy Day," celebrating the iconic sitcom's first airdate. Many networks air reruns of the show to honor this anniversary.
  • Kamen Rider 555 has two, which come from the input codes the characters use to transform. The main hero Kamen Rider Faiz, and the show as a whole, have "Faiz Day" on May 5th (5/5) after the code 555; while the Deuteragonist Kamen Rider Kaixa uses the code 913 (which is also read as "ka-i-za") and "Kaixa Day" is celebrated on September 13th (9/13). Toei has used both days to announce a new 555 spinoff.
  • Fans of Lost tend to celebrate the show on September 22nd, as September 22nd, 2004 was not only the day that the pilot episode aired, but was also the date that the show began on In-Universe.
  • February 13 (the day before Valentine's Day) is "Galentine's Day", a holiday originating from an episode of Parks and Recreation, where women take time to celebrate with their female friends.
  • Festivus is a non-commercial alternative to Christmas invented by author Daniel O'Keefe. When O'Keefe's son Dan wrote a version of Festivus into the Seinfeld episode "The Strike," the holiday became widely popular among Seinfeld fans. On December 23, they often celebrate by following the Festivus "traditions" introduced in the show, such as putting up aluminum poles, airing the year's grievances, and having a "Feats of Strength" wrestling match. Pittsburgh holds a yearly Festivus ceremony featuring these traditions as well as a Seinfeld trivia contest.
  • November 10th is official Sesame Street Day, established in New York City to acknowledge the show's anniversary.
  • Star Trek:
    • September 8 is Star Trek Day, as that was the date that Star Trek: The Original Series premiered in 1966.
    • June 16 is Captain Picard Day, as that's the date that corresponds to the stardate of the Star Trek: The Next Generation episode, "The Pegasus", which featured it.
    • April 5 is First Contact Day, as Star Trek: First Contact said that April 5, 2063 was the date that humans confirmedly made First Contact with an alien species, the Vulcans. According to co-writer Ronald D. Moore, he picked April 5 because that was his oldest son's birthday.
    • In some corners of the Star Trek: Voyager fandom, January 29th (the original air date of "Threshold") is celebrated as Threshold Day, with fanart, memes, and a general consensus that Chakotay made the wrong call in leaving Janeway and Paris' offspring on the planet.
  • The Suite Life of Zack & Cody: The episode "When in Rome," which premiered and is set in 2009, has the twins try to get into a fancy restaurant in Rome, only to be told the next available reservation is November 16, 2023 (with Zack protesting, "What if I don't feel like Italian that day?!"). When that date finally arrived, fans posted the scene all over social media, wondering if Zack feels like Italian after all. Even Google included a banner acknowledging the reservation when searching up Dylan and Cole Sprouse. Both twins' actors responded to the viral date by posting social media screencaps of all the messages and comments they got telling them their table is ready.
  • Mister Rogers' Neighborhood:
    • May 23 is 143 Day. 143 was a number Fred Rogers used to represent the phrase "I Love You", and the holiday is celebrated on the 143rd day of the year. There have even been calls to make this day a public holiday in the United States.
    • Any Friday the 13th is seen as King Friday's birthday, as that is when he was born.
  • National Power Rangers day was co-created by Hasbro and Saban; it is celebrated on August 28, as that was the day the first ever episode of the franchise ("Day of the Dumpster" from Mighty Morphin' Power Rangers) aired.
  • July 10th is officially recognized by the Japan Anniversary Association as Ultraman Day. This is because, one week prior to the premiere of the first episode of the series, Ultra Operation No.1, Ultraman made his first publicly televised debut in a special promotional event named ULTRAMAN Eve: The Birth of Ultraman that was pre-recorded at Suginami Koukaidou Hall. It introduced Ultraman, the Special Science Search Party members, the kaiju he will be facing, as well as a guest appearance by Ultraman creator Eiji Tsuburaya himself.
  • The Walking Dead: In Season 4, Hershel jokingly suggests moving "Spaghetti Tuesday" to "Spaghetti Wednesday". Fans have adopted this and are known to post memes declaring each Wednesday to be Spaghetti Wednesday.

    Multiple Media 
  • May 25th is known as "Towel Day" and celebrates the work of Douglas Adams. Fans carry around a towel due to a passage in The Hitchhiker's Guide to the Galaxy (and an earlier reference in the preceding radio series) that praises the versatility of towels for interstellar hitchhikers. May 25th doesn't have any particular meaning in the fandom (FYI, the anniversary of the first radio broadcast is March 8th), the anniversary of the death of Douglas Adams is a few weeks earlier and it took time to set up the first Towel Day.
  • On July 10th, Japan celebrates Ultraman Day in honor of the eponymous hero. This is because the pre-series stage show "ULTRAMAN Eve: The Birth of Ultraman" was broadcast on July 10th a week before the first episode of the 1966 series aired.
  • Kagerou Project fans usually observe August 15, as it is the established day of its most famous song "Kagerou Daze" and the day when most of the cast get sucked into the Heat Haze world.
  • Regional example: On July 13th, 2004 Pittsburgh, PA officially declared "Jeff Goldblum Day" to honor the actor who was born in that city and performing in a local production of The Music Man at the time. In 2018, a Pittsburgh tattoo parlor/cafe seized on the date to throw a Goldblum-themed celebration, which proved so popular with locals that it was held again the next year — and, as documented in the "Tattoos" episode of The World According to Jeff Goldblum, saw a surprise appearance by Goldblum himself. Sadly, the Coronavirus Pandemic scuppered a 2020 event.
  • Fans of Winnie the Pooh celebrate "National Winnie the Pooh Day" on January 18, the birthdate of Pooh's creator, A. A. Milne. The holiday is also officially acknowledged by Disney.

  • On March 11th of every even number year since 2000, 311 performs an extended concert, either in New Orleans or Las Vegas. Initially a one-night show, 311 Days in The New '10s have extended over two nights.
  • A somber variant: Buddy Holly and his band died in a plane crash on February 3rd, "The Day the Music Died." To honor him, fans hold memorial concerts on February 3rd every year at the Surf Ballroom in Clear Lake, Iowa, the site of the band's final performances.
  • September 21st is a common day to celebrate Earth, Wind & Fire, due to the first lyric in their song "September" - "Do you remember the 21st night of September?" Los Angeles made this date an official holiday to celebrate the band in 2019.
  • A common joke is to reference Green Day's "Wake Me Up When September Ends" on October 1st. Those who know the song was about the death of Billie Joe Armstrong's father are less inclined to joke about it, however, and the band itself has asked fans to stop posting said memes.
  • "The Gummy Bear Song" is often celebrated on November 13, as it is the day that was stated to be when the Gummibär album will be in stores at the beginning of its music video.
  • Hatsune Miku is celebrated on Miku Day (March 9th), due to the Goroawase Number 39 (or mi-ku) being associated with her character. This is also officially observed by Crypton Future Media through events and concerts.
    • Also common is the celebration of Miku's birthday (the anniversary of her original release) on August 31st.
  • Another Memetic Mutation plays off *NSYNC's "It's Gonna Be Me", which decades later was mutated into "It's Gonna Be May", which is always posted when May 1st is coming.
  • Motörhead fans often celebrate May 8th, or the 8th of May, since it sounds similar to their Signature Song "Ace Of Spades". They also call Christmas Eve (December 24th) "Lemmymas", as that was Motörhead frontman Lemmy Kilmister's birthday.
  • Brazil celebrates a "World Rock Day" on July 13th, so chosen for being the day of Live Aid in 1985 (with reports that Phil Collins asked for such remembrance in his concert).
  • Daft Punk fans celebrate September 9th, also known as 909 Day to some. On that day in 1999, the robot characters were born after a supposed accident in the studio. The number 9 was picked after the Roland TR-909 drum machine, hence the nickname 909 Day.
  • International Rush Day is on the 21st of December (21/12) due to their album 2112 and its title track. Fans of the band may put aside twenty minutes of their day to listen to the song.
  • Many fans of Aphex Twin consider the 14th of April as Aphex Twin Day; naturally, this is in reference to the artist's beloved Lonely Piano Piece, Avril 14th.

    Professional Wrestling 
  • WWE and wrestling fans around the world started to celebrate the ""Stone Cold" Steve Austin Day" on March 16 thanks to the numbers that made this wrestler famous, the 3:16. The celebration became officially recognized by WWE in 2020, when the Monday Night Raw of March 16 became a "Stone Cold Day" with the same Steve Austin celebrating in the stage.

  • Following the fourth quarter collapse of the Atlanta Falcons in Super Bowl LI against the New England Patriots, March 28th since that game has become a day many Falcons fans dread, due to being reminded of the lead the Falcons held (3-28) before the Patriots began their Miracle Rally.
  • After the Cleveland Browns finished 0-16 in 2017, with the 2-year record of 1-31, many Browns fans mockingly celebrate January 31st (1-31) as "Hue Jackson Day", in "honor" of their then-head coach.
  • The Australian state of Victoria has two official public holidays for sporting events - Melbourne Cup Day (the first Tuesday in November) and the Friday before the AFL Grand Final (traditionally held on the last Saturday in September, but these days occasionally held on the first Saturday in October instead).
  • Major League Baseball: In 1999, New York Mets third baseman Bobby Bonilla managed to swindle his team into a deferred-contract deal that (despite the fact that Bonilla wouldn't be playing for the Mets for much longer) would result in his continuing to be paid a little over a million dollars a year until 2035, to be paid on July 1st each year - a payment which the now long-since-retired Bonilla continues to recieve. Thus, fans celebrate July 1st as Bobby Bonilla Day.

  • Heathers fans celebrate September 1 for Veronica's opening line. This sometimes results in a crossover with "Back to Hogwarts" day in the Harry Potter fandom (see above entry).
    Veronica: September 1st, 1989. Dear diary...
  • Little Shop of Horrors Day is "the twenty-first daynote  of the month of September," cited in the prologue as the day Audrey II came down to Earth.
  • On top of celebrating Christmas Eve, fans of RENT love to reference the musical's opening lyric, "December 24th, 9 P.M." once the clock strikes 9 P.M. on that date.
  • In-Universe, Schroeder in You're a Good Man, Charlie Brown, gets the entire school to celebrate "Beethoven Day," and join in celebration with a song.note 
    Call the principal and hand him the news.
    We've got a holiday that he can't refuse.
    A day of harmony, a day of music:
    Beethoven's birthday!

  • National Barbie Day is March 9, the anniversary of when Barbie was revealed at the International Toy Fair in 1959.
  • Starting in 2019, August 10 is celebrated by BIONICLE fans as "810NICLE Day". The BIONICLEsector01 wiki even commissioned past BIONICLE comic artists to draw new character artwork in observance of the "holiday", including Stuart Sayger's Lesovikk, Randy Elliot's Makuta, and Leigh Gallagher's Trinuma. Project Litestone Studios also released the first build of the BIONICLE: The Legend of Mata Nui REBUILT Game Mod on this day.

    Video Games 
  • Bungie: July 7th (7/7) is "Bungie Day" because of Bungie's obsession with the number "7". This is referenced in-game with posters in Halo 3.
  • Call of Duty: The Zombies fandom has "115 Day" (January 15th), named for Element 115 (now called Aetherium), the source of the zombie infestations the mode deals with.
  • Dragon Age: December 4th is "Dragon Age Day", which was originally spelled "Dragon 4ge Day", but was later changed to prevent confusion with the upcoming Dragon Age 4 game.
  • Halo: Fans tend to unofficially consider November 6th to be "Halo Day", as Halo 4 was released on November 6, 2012.
  • The Last of Us fandom has Outbreak Day (September 26th), the day the fictional cordyceps outbreak started in the universe.
  • For the Live A Live fandom, they like to dedicate the 25th of every month to Masaru Takahara, as a reference to his paltry IQ/Special Attack stat (25, and it can never increase by level.)
  • Mass Effect fans celebrate "N7 Day" on November 7th, a date chosen as a reference to the elite N7 special forces Commander Shepard is a part of.
  • Metal Gear:
    • The Shadow Moses incident in Metal Gear Solid took place on February 28th, and the occasion is often commemorated with fanart.
      • Partway through the game, it is revealed that "Master" Kazuhira Miller had died three days prior. As a result, some fans jokingly celebrate February 25 as "Kaz Death Day".
    • Similarly, Metal Gear Solid 2: Sons of Liberty has Rose and Solidus repeatedly remind Raiden of the date April 30th. The fandom celebrates it as the date of the Big Shell incident (and, jokingly, "Raiden's Terrible, Horrible, No Good, Very Bad Day").
  • Persona 3:
    • January 31st, the date that S.E.E.S. fought Nyx to stop the Fall and save the world.
    • March 5th, the day the protagonist dies after using the Great Seal to stop Nyx, at the cost of his own life.
  • Pokémon:
  • RayStorm: August 4 is celebrated as RayStorm Day; August 4, 2219 is the day that Operation RayStorm begins.
  • Resident Evil: The last week of September, when the Raccoon City outbreak occured in 1998 in the series' canon. To be more specific, fans note September 28th (the day Jill's story in 3 begins) and October 1st (the day the city was nuked).
  • Sonic the Hedgehog: Sonic's official birthday is June 23rd, the date that the original game was released in the US. The date is always marked by SEGA and other official parties, whether it be with new game releases or other events.
  • Splatoon fans celebrate the Squid Sister Marie on March 13, since like Mario Day, it can be spelled as "MAR13."
  • The Stanley Parable: 4/27 (April 27th), referencing Stanley's employee number being 427. Notably, The Stanley Parable: Ultra Deluxe released on April 27, 2022.
  • Super Mario Bros.: March 10th is Mario Day, since the date can be spelled as "MAR10." Originally, Mario Day celebrated anybody named Mario, but it quickly became associated with the Mario. Nintendo has celebrated March 10th as Mario Day since 2016.
  • Touhou Project: The ninth of September (09/09) is "Cirno Day" because the date has two nines, the number associated with Cirno (originally in a game manual). Touhou fans celebrate every year with a plethora of Cirno pictures.

    Visual Novels 
  • Ace Attorney fandom makes references to the first game's fourth trial on December 24th, quoting the memetic phrase "'Almost Christmas' means it wasn't Christmas."
  • When They Cry fans use the first day a loop starts for each series to celebrate. June 19th is considered to be Higurashi day, and October 4th is considered to be Umineko day.

  • In 2003, Ctrl+Alt+Del invented "Winter-Een-Mas," a weeklong celebration of video game culture at the end of January. Fans began celebrating Winter-Een-Mas in 2004, expanding it to include all forms of gaming. Now even Syfy follows the holiday.
  • Homestuck fans celebrate April 13th, the comic's release date and John Egbert's birthday. "413" is also an Arc Number for the franchise, and many important updates were released on that date. To a lesser extent, 6/12 (the start of the Trolls' session and Karkat's "wriggling day"), 10/25 (413+612, another Arc Number and the release of the Wham Episode "Cascade"), 11/11 (the start of the Alpha Kids' session), and the other kids' birthdays in early December get celebrated in the fandom too.
  • The Sleepless Domain fandom celebrates "Keesmas" on July 17th, the anniversary of main characters Undine and Kokoro's First Kiss.

    Web Animation 

    Web Original 
  • Dream SMP:
    • The anniversaries of the days certain streamers joined the SMP are treated as their characters' "birthdays", on top of their real-life birthdays.
    • July 29th is widely celebrated as L'Manburg's Independence Day (or "birthday"), as the beginning of the country kicked off the SMP's storyline and "lore", shaping the server to what has since become. August 2nd is celebrated for similar reasons, but rather for the day L'Manburg won independence, albeit at a high cost.
    • November 16th is widely recognized as the anniversary of the Season 1 finale.
  • Neopets has a number of in-universe holidays, most of which are dedicated to honoring each of the 55 Neopet species. Celebrations usually consist of creating fanworks involving the relevant pet type or character, whether for submission to special themed editions of on-site contests or just for fun.
  • Newgrounds has a couple of celebrations based on some of its most emblematic series:
    • The Clock Crew has "Clock Day" on August 15, referencing StrawberryClock's infamous "B" flash being saved on the portal.
    • The Pico series became so popular on Newgrounds that they celebrate the titular character and his universe with "Pico Day", celebrated on his creator Tom Fulp's birthday April 30.
    • Madness Combat celebrates "Madness Day" on September 22.
  • Fans of OneyPlays have made November 28th "Puhskinti Day" after a joke made by Chris, Ding Dong and Julian while playing Dead Rising. It involves squinting and eating spaghetti, preferably while either naked/wearing a swimsuit.
  • On Tumblr, March 15th is widely celebrated as the Ides of March, with memes coming out of the woodwork every year as a tribute to Julius Caesar getting stabbed. Don't ask why; Tumblr's like that.
  • March 1st is one in the SMPLive fandom, as it is the anniversary of the server's launch in 2019.
  • A memetic example, September 10, 2021, and October 9, 2021 (For DD/MM/YYYY) have been seen as celebrations of the "9 plus 10 equals 21" Vine, with those days often being referred to as "Judgment Day".

    Western Animation 
  • To fans of The Amazing World of Gumball, January 10th is Sluzzle Tag, a holiday invented by Gumball in "The Lie" to get through the post-Christmas January doldrums. The holiday is celebrated by wearing leather, playing Grindcore music, and waiting for "Sluzzle Dude" to come in through the toilet and leave presents.
  • BoJack Horseman fans (as well as Word of God) celebrate January 31st as "Halloween in January," named for the business venture Todd and Mr. Peanutbutter invent in the Season 1 finale. It was also the release date of the show's final episodes.
  • April 30th is Bugs Bunny Day, celebrating the character's first unofficial appearance in 1938's "Porky's Hare Hunt." However, his first official appearance is A Wild Hare, which is July 27, 1940. While Bugs Bunny Day is regarded as April 30, Bugs' official birthday is celebrated on July 27, as evidenced by Boomerang holding a Bugs Bunny Birthday Marathon on July 27, 2020, and Bugs referring to July 27 as his birthday in The Looney Tunes Show.
  • The Fairly OddParents! fans celebrate every March 15 as Denzel Crocker Day, where Mr. Crocker is at his meanest and the day he lost his fairy godparents.
    • Another date fans often celebrate is March 22 as the day Cosmo had an idea (according to Wanda writing it down), especially if it happens to fall on a Wednesday.
  • Gravity Falls fans celebrate every August 31st, as that's the birthday of twin protagonists Dipper and Mabel.
  • According to the website Equestria Daily, the 1st of March is Derpy Day, named in honor of the first appearance of a then-nameless background pony with mismatched eyes in the pilot episode of My Little Pony: Friendship Is Magic. The fandom attached to this one irregular pony, and theorized pages of minutiae about her. Derpy Day is celebrated by baking or eating muffins, and handwriting letters to friends.
  • Lilo & Stitch franchise:
    • Fans of the franchise celebrate "Stitch Day" or "626 Day" every June 26, in reference to his experiment number 626. Disney has since embraced this day with special marketing on that day.
      • Since 2015, the day also carries some significance with LGBTQ+ Lilo & Stitch fans, as June 26, 2015 was the date the Supreme Court of the United States ruled in Obergefell v. Hodges that bans against same-sex marriage are illegal under the Fourteenth Amendment. This was embraced by openly gay original film co-writer and co-director Dean DeBlois, who drew a colored sketch of Stitch waving a rainbow pride flag and Lilo's rag doll Scrump waving a blue flag with a golden-yellow equal sign, the logo of the Human Rights Campaign, and tweeted it on that date. Stitch himself is now considered a minor LGBTQ+ icon representing LGBTQ+ families, befitting the franchise's focus on non-traditional families.
    • Furthermore, some fans tend to expand their celebrations to a whole "Stitch Week" beginning June 21 (the anniversary of the first film), with said fans celebrating "Angel Day"note  on June 24, "Reuben Day"note  on June 25, "627 Day"note  on June 27, and "Leroy Day"note  on June 29.note 
  • To celebrate the release of the movie, the mayor of Toronto declared August 20th to be "PAW Patrol Day".
  • The Simpsons:
    • Any Thursday that lands on the 20th of a month is worth celebrating, thanks to the appearance of a fictional rapper named Thursday the 20th in the episode "Pranksta Rap".
    • Simpsons fans also celebrate June 5th as The Feast of Maximum Occupancy, as seen in "Homer the Heretic".
  • South Park:
  • SpongeBob SquarePants: In "Employee of the Month," when SpongeBob asks Squidward if he knows what today is and Squidward snarks if it's "Annoy Squidward Day," SpongeBob tells him that that's on the 15th and shows a calendar with the date marked. Fans deduced that "Annoy Squidward Day" took place on February 15th and began celebrating it as such, with even the official Twitter account joining in the fun.
  • To celebrate the anniversary of his debut appearance in Steamboat Willie, Mickey Mouse Day is acknowledged on November 18.