Reruns, I guess? Trying to think of what aired in the weeks after 9/11, when a bunch of new stuff got delayed, and the studio techs were as fried as everyone else. Marathons of evergreen daytime programming. So then as now, probably Star Trek: The Next Generation.

America's closest real comparison might be radio DJs putting on a long song so they can go take a shit. "November Rain?" Buddy, ease off the nachos.