Leap Day in cartoons
February 29 brings that quadrennial leap year-defining day, Leap Day. More specifically (as NPR explains), leap years happen in years divisible by 4, but not in years divisible by 100 (unless the year’s divisible by 400). So 2000 was a leap year, but not 1900 or 2100.
Several famous figures call Leap Day their birthday, such as rapper Ja Rule. Leap Day also extends to the world of comics and animation, as shown in the examples below.
Superman
Given comics’ inconsistency, the most famous superhero, Superman, has been given various in-story birthdays over the years—everything from April 18 to December 1. However, February 29 is the most popular date, and the one that’s mostly stuck. The February 29 birthdate was first stated in the letter column of “World’s Finest” #164 (February 1967), with the editor telling a reader that Kal-El was born on a date on Krypton that corresponds with Earth’s February 29. This date also appeared in the 1976 Super DC Calendar, a wall calendar DC published with various in-story DC Universe-related dates.
Superman’s birthday is prominently featured in “For the Man Who Has Everything,” a story published in “Superman Annual” #11 (1985), and written by Alan Moore. In this story (set on February 29), the villain Mongul (thanks to a hypnotic, coma-inducing alien plant) has our hero mentally trapped in a fantasy world where Krypton never blew up, and Clark is living out his life on Krypton. Meanwhile, Batman, Robin (Jason Todd version), and Wonder Woman, who’d arrived at the Fortress of Solitude to celebrate Superman’s birthday, try to save their friend and stop Mongul. This story’s been adapted to TV several times, including an episode of “Justice League Unlimited” and (with Kara replacing her cousin) a 2016 episode of “Supergirl.”
Time magazine also cited February 29 as Superman’s birthday, in a special 1988 edition celebrating Superman’s 50th anniversary. As recently as 2016, DC used February 29 as Superman’s birthdate to promote the then-upcoming movie “Batman V Superman: Dawn of Justice.”
If wondering, Clark Kent’s “birthday” is celebrated on the day the Kents found his rocket. Various dates for the rocket landing have been given (again, comics), ranging from sometime in spring to early winter. Meanwhile, most 1960s-1980s stories (plus the aforementioned 1976 DC wall calendar) went with June 18. In real life, “Action Comics” #1 (Superman’s debut issue) was published with a June 1938 cover date. June 18 is also the birthday of Bud Collyer, the voice of Clark on the 1940s Superman radio show.
Captain Marvel/Shazam
Fawcett and DC Comics’ Captain Marvel chose February 29 as his birthday. This came from a Golden Age storyline (in “Whiz Comics” #47 (October 1943) and “Whiz Comics” #52 (March 1944)) about Captain Marvel needing an actual birthdate to register to vote. Apparently, the day he first debuted as a superhero wasn’t good enough?
This was when Captain Marvel and Billy Batson were considered two separate people, of course; most modern stories treat Cap as just an adult guise of Billy. Billy celebrates his birthday on a different date—December 23, per the 1976 DC Calendar, though other dates have been given elsewhere.
Green Lantern
“The Leap Year Menace” was the backup story in “Green Lantern” #3 (November-December 1960). Here, Hal Jordan (as Green Lantern) tries to avoid getting married to Carol Ferris, per a tradition stating women can propose to men on Leap Day. (Yes, I know...) In order to avoid Carol’s proposal, Hal conjures up via his power ring a “chiller-diller” monster to fight as a distraction. Hijinks (and chaos) ensue.
The story’s definitely of its era in terms of tone, assumed social/gender roles, etc. Outside of hardcover/trade paperback collections, it's only been reprinted by itself once, in a 1976 anthology comic. (1960 and 1976 were both leap years.)
If wondering, a “chiller-diller” is old slang for horror films and their monsters, particularly the style seen in Hollywood's Golden Age.
Hero Elementary
On the PBS Kids animated series “Hero Elementary,” student hero Benny Bubbles’ birthday is on February 29. This was probably chosen by the writers as a leaping pun, since Benny uses his bubble-based powers to leap long distances.
Why do we have leap years, anyway?
Finally, just why do we have leap years and leap days? CGP Grey of YouTube explains it all pretty well in this video.