Why are prime-time network TV shows shown at different times, depending on the time zone?

Hey, Matt:

Why are prime-time network TV shows shown at one time in the Eastern and Pacific time zones and another time in the Central and Mountain time zones?

-- Phil Collins, Oceanside

Heymatt:

Why do TV programs air one hour earlier in the Central time zone? One often hears "8 Pacific, 7 Central." I assume the same program airs at 8 in all other time zones?

-- Jane Bonderson, the net

Let's go back, back, back in time, to the late'40s. The war is over, and TV is just taking off. Your home screen is barely the size of a salad plate, but already people are arranging their schedules around The Howdy Doody Show. Well, the few thousand who actually have sets. New York is the main TV production and transmission center. Programs are fed by land lines (coaxial cable, some shared with the phone company) to the growing number of local affiliate stations, most of which are in the East and Midwest. Buffalo Bob and Howdy goof around with the kids in New York at, say, 5:00 Eastern time, and it's fed live over the network, which means Chicagoans see it at 4:00, Central time. Some Mountain-time affiliates take the shows two hours earlier, Pacific three hours. But in the Pacific zone, many shows arrived in town by kinescope and were broadcast out of Los Angeles at a more reasonable hour. (Even into the '70s, Hawaii was receiving network TV on tape that was shipped by airplane from New York, delaying broadcast by a full day.)

So right from the beginning, Eastern and Central time zones were treated as one "broadcast area," with Pacific and Mountain arranging their schedules as they could, given the technology available. In the early 1950s, most network affiliates were only on the air 80 hours a week, and about half of that was network programming fed out of New York or Chicago.

Even after local affiliates had the ability to videotape the East Coast feed and play it back whenever they liked, the Central time zone continued to broadcast the New York feed simultaneously, that is, an hour earlier Central time. It was (and still is) cheaper for the network to do one feed for two or three zones, and there was (and still is) the idea that Midwest = farms = early to bed, early to rise. Nobody is going to stay up until 12:30 a.m. to watch Letterman if they have to get up at 4:00 a.m. to milk the cows. And while that's less true now than it was in the '50s, Midwesterners still want their prime time to start and end an hour early.

Now everything's fed from New York via satellite to local affiliate computers, one feed for East/Central/Mountain stations, another for Pacific. Mountain-time affiliates delay broadcast by one or two hours, depending on which schedule they're following. Network news is fed closed-circuit more or less continuously all afternoon, with updates, for locals to rebroadcast according to their own news schedules. But even though the Central zone could change prime time, people just like it the way it's always been. Given network competition, things are unlikely to change unless there's some overwhelming economic reason to do so