Supergirl, The Flash, Arrow, and Legends of Tomorrow Get Expanded Runtime For Invasion! Crossover

The CW recently adjusted its programming schedule for next week, giving each of its four DC Universe superhero shows an extra 30 to 50 seconds during the upcoming four-way crossover event.

According to their tweaked timing information, Supergirl will run an extra 35 seconds on Monday; The Flash will run 50 additional seconds; Arrow will get 40 more seconds; and DC's Legends of Tomorrow will run for an extra 45 seconds.

It's unlikely the time will make a big difference to the episodes; it's more likely that they needed an extra ad spot, or just an extra little bit before cutting a scene, and that expanding the time slot allowed The CW to both keep everything they wanted to keep and also still run mid-credits ads for the shows' midseason finales, which will air the following week (except for Supergirl).

It isn't uncommon for The CW to ever-so-slightly expand the time given to its DC shows in key episodes, such as midseason or season finales. Last year, there was additional time given to the The Flash/Arrow crossover which launched Legends of Tomorrow.

Arrow, The Flash, and Supergirl will cross over with DC's Legends of Tomorrow next week in "Invasion!" a three-part crossover that starts in the final moments of an episode of Supergirl and then plays through the other series. Based on the 1988 comic book event miniseries Invasion! from Keith Giffen, Bill Mantlo, Todd McFarlane, Bart Sears, and the crossover -- with its marketing title "Heroes vs. Aliens" -- will closely track the plot of that storyline: aliens will be assembled by The Dominators and descend on Earth to bring an end to the "threat" of Earth's burgeoning metahuman community.

In the comics, the Dominion were secretly hoping to build their own super-race, and as a result created a handful of new superheroes in the course of the story.

In the TV version, rather than assembling a loose alliance of dangerous alien races, the Dominators will apparently be mind-controlling the aliens that join them. That's a revelation that suggests even the heroes might be forced to take one another (or at least the alien Supergirl) on at some point in the story.

Supergirl airs Mondays at 8 p.m. ET/PT; The Flash on Tuesdays at the same time; Arrow on Wednesdays and DC's Legends of Tomorrow on Thursdays. All four series air on The CW. The "Invasion!" crossover will air beginning November 28.