One of the most common TV questions is "why is prime time an hour early for the Central/Mountain zones"? The answer for the Central zone is easy; the networks don't want to be bothered with putting out a Central only feed. But why the Mountain zone? Until 1986, there were no Mountain zone feeds and stations in that zone had to tape programs and air them later. Then why did they decide to start at 6:30 (7pm after 1971)?