TV Prime Time
I would never have given this any thought but my sister used to live in Tennessee which is split in two time zones. Whenever I'd visit, I'd think, "Hey, this isn't an 8 o'clock show!"
If you ever listen to old radio serials, you'll notice that the actors gave one performance for the east coast and one for the west (the Blue and Red networks). The actors in a lot of programs, especially Fibber McGee and Molly, downed a couple of cold ones between show times. The later shows are almost always funnier with drunken ad-libs and blown lines. With the FCC's mandated delays, we won't hear anything like that anymore.