I've enjoyed watching classic "What's My Line?" (& "I've Got a Secret") for a long time on GSN (and now on MeTV). Something that I've wondered how the Mountain and Pacific time zones got the broadcasts in the early/mid '50s, as the are announced as "Live from New York".
Thanks
By 1951 AT&T had set up a transcontinental coax cable network for the television networks. So stations not on Eastern time would point a film camera at a kinescope monitor and record the live show. They would then rush the film to be processed in time for them to play it back at their proper local time.
This is one of the major motivations for inventing the quicker, cheaper technology of videotape to replace kinescope films.
Before that, networks would fly film copies of programs to the west coast for transmission. Obviously, these would air at different times.
If you notice, at the end of nearly every program, John Daly says to check your local listings for the time and station. In the early days of TV, some markets just had one or maybe two stations trying to cover 4 networks, so they would often time shift programs to try to fit it all in. They did it all using kinescopes and would sometimes air at different times from the original network feed.