OK, so you're hunkered down in your favorite chair at 10 p.m., ready to watch "Law & Order." (search

Life is good.

But there's trouble in TV paradise: The show's already started - and you've missed a minute or two of your favorite series.

What gives?

It's called starting a show "off the clock" - a few minutes early or late - and it's becoming a semi-regular occurrence across the prime-time landscape, particularly on NBC.

Last Thursday, for instance, "Friends" (search) began promptly at 8 p.m. - but instead of ending at 8:30, it ran until 8:32 before segueing into an hourlong episode of "The Apprentice." (search

Only problem is, "The Apprentice" didn't run for an hour - it ended at 9:28 p.m.

That can make taping a show on your VCR - or programming your TiVo - extremely frustrating.

Off-the-clock programming "has the potential to be good, but it also has the potential to irritate," said industry analyst Bill Carroll of Katz Media.

"I think what ends up happening is that viewers end up switching over to something else in progress - and they get irritated."

NBC started its recent spate of off-the-clock programming when it began airing "supersized" episodes of "Friends" to capitalize on the show's huge audience.

These episodes run over the standard 22 minutes, sometimes up to 35 or 45 minutes. The Jan. 8 episode of "Friends," for instance, started at 8 p.m., but ran until 8:37.

The way the networks see it, the more airtime a top-rated show like "Friends" can eat up, the more ads they can cram in - and that means more money to be made.

"We don't want to irritate anyone," says Mitch Metcalf, NBC's senior vice president of scheduling.

"If we can get a longer episode of 'Friends,' we're satisfied because we're giving our viewers more of what's probably their favorite show.

"And those few extra minutes of 'Friends' equals ratings, which never hurts."

Those "few extra minutes" can also cut into the competition's audience - which is another reason the networks use off-the-clock scheduling.

Industry maven Marc Berman of Mediaweek calls it "a very bad strategy.

"A 75-minute 'Fear Factor' on NBC might cut into the viewership for 'Everybody Loves Raymond' (search) on CBS, but I think it's angering viewers," he said.

"The networks should keep their schedules consistent and keep the shows where they belong.

"They don't want to start confusing viewers in an atmosphere where there are other choices."

But NBC's Metcalf says, "We don't do it to annoy people, contrary to what people think. When a hit show can deliver more program time, that's something we often don't want to pass up."