Copyright: bowser day
August 4 is Bowser Day, an unofficial International Holiday created on July 1st, 2012 by the FurAffinity user, Dragonnis.
Originally taking place on August 6th (the creator's birthday), Bowser Day was moved to August 4th because World 8-4 is the first true physical appearance of the King of Koopas in the original Super Mario Bros..
Similar to Super Mario Day (Mar. 10th), fans of the Super Mario series, and specifically the character Bowser, celebrate by sharing their favorite depictions, memories, and experiences with the aforementioned character. They also tend to produce a bunch of fan material, art especially and even writing, dedicated to the character. Or making the wiki page on Bowser Day.
Oh, and a sudden spike in Rule 34 focusing on Bowser suddenly appears for some reason. What ever could it be?
Note: It should be mentioned that users on mainstream sites like Twitter, Facebook, and Instagram are using the term Bowser Night and similar for NSFW posts. Posts should be tagged Bowser Day regardless if the source uses Bowser Day or Bowser Night.
More Information
Bowserday.com
Bowsernight.com
Bowser Day/Night gallery sites made by Puns4lyfe.