Real-world time is, as you’d expect, the time that passes between when two stories are published. For example, it’s been 45 years since Spider-Man first appeared in Amazing Fantasy #15 (Aug. 1962).

In-story time is the time that passes within a story. So even though it’s been 70 years since Superman first appeared on the newsstand, it’s only been 10–15 years since his debut within the DC Universe.

The tension between these two leads to a strange, fluid take on time, which has its own issues.

But then you get into time travel and cosmic retcons, and in-story time can’t quite explain things.

Let’s take Earth-51. At the end of 52, it was revealed that the universe had spontaneously created 51 copies of itself, all identical. This multiverse was then attacked by a creature that essentially ate time, altering these worlds’ histories so that each universe was different from the others.

The universe containing Earth-51 was destroyed Countdown. A new copy of the main universe then formed to fill the void.

So what was Earth-51 like two years ago? In real-world time, it didn’t exist. In story time—well, that depends. Two years ago in the DC Universe was before Infinite Crisis, which means it was before the new multiverse was created. But each universe has a full history. You could go to Earth-51, go back in time, and it would be there.

Now suppose there’s a third type of time, sitting between real and in-story time. Cosmic time takes place within the story, but tracks retcons, time travelers, etc. Instead of a single timeline, you’d see a series of layers, each layer being the result of some alteration of history.

To switch gears for a moment, let’s look at Back to the Future. Marty McFly travels from 1985 to 1955, changes history so his parents never get married, then changes history so that they do, but under different circumstances. The two possible versions of 1985 are simultaneous, internally to the story. But from the perspective of Marty traveling through time, or of the audience, the version at the end of the film takes place after history has been changed.

For the most part, it’s taking the order of events from real-world time and giving it a meaning inside the fictional world. Now it makes more sense to talk something being the post–“One More Day” version of something that happened before the events of “One More Day.”

And so we come to it at last… Blog Action Day has now officially begun for the first countries closest to the International Dateline.

I realized that it wasn’t going to stop after 24 hours the way that, for instance, Slashdot’s April Fools days run (GMT midnight to midnight). The event was designed to be October 15—not October 15 in a particular time zone. If you start with the first zone to reach a date, and run through the last zone to finish it, “October 15″ would last about 48 hours.

I’m too sleepy to do the math myself, so I’ll trust Wikipedia’s entry on Time Zones:

Because the earliest and latest time zones are 26 hours apart, any given calendar date exists at some point on the globe for 50 hours. For example, April 11 begins in time zone UTC+14 at 10:00 UTC April 10, and ends in time zone UTC-12 at 12:00 UTC April 12.

So there you have it: a worldwide event tied to a calendar day but no time zone lasts 50 hours.

And here you thought things moved faster on Internet Time!

This is hardly unique to superhero comic books. The same is true of James Bond movies, the Hardy Boys and Nancy Drew books, and even newspaper comic strips. (How long has Dennis the Menace been five years old?)

Still, it makes for interesting contradictions. If Superman debuted 14 years ago, he can hardly have met JFK, so clearly any stories dealing with him are no longer “canon.” On the other hand, if the story doesn’t depend on JFK having been the President at the time, the nefarious super-villain plot may still be part of Superman’s history. But sixty years of chronicled adventures crammed into fourteen years makes for a pretty busy life! (And how frequently does the US hold Presidential elections in the DC and Marvel universes?)

The time-squishing effect is easiest to see with flashbacks. Stories originally set in the 1950s, and told with 1950s sensibilities, are supposed to have taken place only 5-10 years ago, setting them in the 1990s. When they get retold, in whole or in part, the setting, storytelling, visual design, and even dialog are usually updated. A few years ago an origin story for the Flash showed a young Wally West. In his room there was memorabilia for Star Trek: The Next Generation, and yet the character first appeared a decade before the original Trek! This effect was poked fun at in a Teen Titans story a few years ago. It was told in full 1960s mode, and at the end it turned out to be a story told to Impulse, who complained that “People didn’t really talk like that when you were a kid!” And he’s right, within the context of the comic book. But outside that context, he’s wrong.

Actually the Titans make an interesting case, as they’ve been allowed to grow up, but their mentors, the Justice League, have (for the most part) not been allowed to grow old. The original Teen Titans, depending on author, editor, and story needs, are now anywhere from 24-29 years old. The Justice League seems to be mainly in the 25-35 range. That’s a lot of overlap, and you can easily end up with very small age gaps between mentor and sidekick.

There are exceptions. Time passes normally in comic strips like “For Better or For Worse,” in which the Patterson children have grown up year by year, the oldest starting his own family. Time also passes normally (or close to it) in The Sandman, with the same number of years passing from the now in Preludes and Nocturnes to the now in The Wake as passed during the series’ publication. (This makes for yet another contradiction, as the series is nominally set in the same universe as Superman and the rest.) But Johnston and Gaiman are exceptions. The vast majority of comic books pass in a bubble of slow time, and the vast majority of comic strips are frozen. Charlie Brown, Calvin and Dennis will never grow up. Jason Fox will be a child genius forever. As long as Superman, Batman and Wonder Woman remain popular, they will never get too old in their mainstream books (alternate universes notwithstanding).