Unique timeslot?

They used to do it all the time back in the 60's. Back then, "Prime Time" started at 7:30, and it was quite common for shows to run from 7:30-8:30, 8:30-9:30 (but as far as I can recall, very rarely anything from 9:30-10:30; seems they preferred 10:00-11:00).

On Fridays night, shows like THE WILD WILD WEST, TARZAN and STAR TREK all ran from half-hour to half-hour. THE OUTER LIMITS was originally on Monday noights at 7:30-8:30 (what blows my mind about that was a show THAT SCARY on that early!).

This could make it difficult for viewers to switch channels if a show on one network ran on the half-hours but another ran on the hours. The tendency might be to stic with whatever was on one network for the whole night.

Once the 7:30-8:00 slot was given over to local stations, hour shows running on the half-hours pretty much vanished.

Another thing that was quite common back then were 90-min. TV movies. This went for tings like THE ABC MOVIE OF THE WEEK (an entire series of stand-alone made-for-TV movies), or THE NBC MYSTERY MOVIES (rotating regular series where each episode was 90 min. istead of 2 hours). Again, when the 7:30-8:00 splot was lost, pretty much all "tv movies" became 2 hours (including commercials).

If I remember correctly, they did this because they didn't want to go up against the Simpsons at 8, because at the time the Simpsons was on Thursday nights as well, but felt that 9 was too late to get the children viewers.

It was also up against Cosby too. That's why they started it at 8:30.