Adult Swim, Cartoon Network's block of stoned-college-student-oriented programming, has been one of cable's biggest ratings successes. The block of shows, which includes a mix of original animated and live-action series, plus reruns of various Seth McFarlane cartoons, has recently dominated late night. In 2013, Cartoon Network finished No. 1 from 11 p.m. to 1 a.m.—only recently dropping below The Tonight Show during Jay Leno's last hurrah.
Meanwhile, Dan Harmon's Rick And Morty recently even bested the primetime lineups of the big broadcast networks in the hard-to-reach demo of young males that Adult Swim's skews heavily toward. Viewers are also more likely to watch Adult Swim shows live, whereas late-night talk shows are often consumed in the form of clips on other people's Facebook feeds. So, flush with success, Adult Swim is expanding again by starting an hour earlier, with the programming block now running from 8 p.m. to 6 a.m., beginning March 31.
Originally broadcasting only from midnight to 2 a.m., Adult Swim has steadily grown over the past 10 years, airing kids' cartoons long after kids should be in bed, and creeping both earlier and later. The network says it will continue its current practice of debuting new programs at 10:30 p.m., then moving them around the schedule once they've built an audience. As such, that 8 to 9 p.m. hour will initially feature reruns, but the move obviously gives Adult Swim more real estate in which to expand its slate of original shows down the line. And with the expansion, it moves it even closer to taking over primetime as well as late night.