Remember when America went to bed?

I was watching "Poltergeist" this afternoon for the first time in more than 20 years when I was struck by another way our country has changed.

You may not recall that when the movie starts, the first thing we hear is the National Anthem. As it continues, we see a man who has fallen asleep in front of the television. The anthem is playing because the station is signing off for the night.

As the anthem concludes, the TV screen goes to white -- nothing but static.

Do TV stations sign off anymore? Maybe I'm jaded because I live in Los Angeles or maybe I just go to bed too early these days, but I think most stations these days broadcast around the clock. If there isn't any original programming to put on the air, there are always infomercials and old movies.

I remember when I was living in Reno, I caught "Tarantula" and "Lord Love a Duck" in the middle of the night on a UHF station out of Sacramento. Movies like that aren't on in prime time. One night in Houston, when I had to be up at 5 a.m. to go to the airport, I watched three hours of "Outer Limits" reruns -- complete with 24 airings of the same Cal Worthington commercial.

Face it, we're a 24-hour society now.

When we were in high school, nothing was open in the middle of the night except for a few convenience stores, the rare drug store and a couple of all-night diners. Now you can shop for almost anything any time of the day or night if you live anywhere near a good-sized city.

Progress? Maybe, but I miss those old signoffs.