@Dutchess_III Kansas is central time zone, so the east coast is one hour ahead. When it’s 10 in Kansas, it’s 11 in Florida. There are 4 time zones in the contiguous 48, Pacific, Mountain, Central, and Eastern in that order west to east. If it’s 7:00 in PT, it’s 8:00MT, 9:00CT, and 10ET. Most live shows are live simultaneously in CT and ET, and replayed at an appropriate hour in MT, and PT. Exception can be a sports game or presidential address, where it might be shown live in all time zones, there are exceptions.
As said above, 11:00pm TV shows in ET, are shown at 10:00pm CT. So all those really good TV shows we stayed up late for in NY, and didn’t get to go to sleep until midnight, the people in Chicago only had to wait until 10:00 for the show to start, and got to bed at a decent hour. Also, in CT I can watch The View at 10:am, and get out of the house before noon, but back east i have to wait for it to start at 11:00am, and then half the day is over.
The Tonight Show moved from NY to California during Johnny Carson’s tenure, not that it matters, and with Johnny it was live at 10:30 CT and 11:30 ET, and replayed for MT and PT. So, FL is 11:30pm in this instance.
Most prime time shows in Seattle are shown at the same hour as ET at Seattle local time. So, an 8:00pm ET show (the beginning of prime time in Florida) is shown at 8:00 PM Seattle time. Day time shows can vary more, because of the content of the show. For instance, The View is shown at 10amCT, 11amET (live) and replayed in Seattle I think a totally different time in the afternoon.
Prime time and late night TV were following rules because of content. Meaning, what was appropriate for children to watch.