NEW YORK -- The natural rhythms of television used to be as dependable as leaves sprouting in spring and falling in autumn.
Broadcast networks would premiere new shows in mid-September, then replace failures when the weather turned cold. Summer was rerun season. Prime-time schedules rarely changed.
Those days are long gone.
Series pop up and disappear anytime, dispatched around the schedule like chess pieces. Some shows are rerun all the time, others never. You can't even count on a show to start at the top of an hour anymore.
For ABC, CBS, NBC and Fox, plus upstarts WB and UPN, the landscape is changing rapidly. The reasons include viewers' lackluster response to the current season, cable continuing to grab viewers and awards, and the hyper-competitiveness of TV executives.
For viewers, their trusted TV sets can be confusing. Here's a look at how things are changing and why:
NEW SHOWS ALL YEAR ROUND
Gail Berman wants to put a sign up for Fox viewers: We never close.
The Fox entertainment president is an enthusiastic proponent of all-season scheduling - starting new shows all the time, not just in the fall. The summer will no longer be a wasteland.
Violating one of TV's formerly sacrosanct rules, most of Fox's big winners lately have avoided fall premieres. "The O.C." debuted last summer. "The Simple Life" came in December. Fox's centerpiece, "American Idol," began again in January and is dominating the ratings.
NBC entertainment chief Jeff Zucker also said he would premiere many of his network's new 2004 shows this August, right after the Summer Olympics. "A lot of the folks who don't understand some of the moves that we and others are making are playing by the old rules," Zucker says.
In its infancy, television had a year-round approach. But as live programming gave way to filmed shows, and stars began expecting summer vacations, start dates drifted toward the fall. In the early 1960s, ABC instituted a September "premiere week" to attract attention, and other networks followed suit, says Tim Brooks, co-author of "The Complete Directory to Primetime Network and Cable TV Shows."
"Once they got into the routine," Brooks says, "nobody wanted to be the one to break out of it."
Television executives believed there were fewer viewers in the summer because people stayed outside longer. So summer is where they stuck the leftovers.
Cable networks recognized the vacuum and filled it with their best material, siphoning viewers away from the networks. And the surprise summer success of broadcast shows like "Survivor" and "Who Wants to Be a Millionaire" upset conventional wisdom by proving people will watch TV whenever there's something worth watching.
Still, executives at CBS, the nation's No. 1 network, gently mock the idea of fiddling with TV's clock.
"If you launch a bad show in August, it's still going to be a bad show in September," says CBS Chairman Leslie Moonves. "Let me ask you a question. Would (NBC's) 'Coupling' have worked any better in August?"
"We're doing just fine playing by the same old rules."
The old TV model called for series to run year-round, with a couple dozen new episodes and a round of repeats.
HBO changed that. Its runs series for 13 weeks, often less. Then the show disappears until new episodes are ready - "The Sopranos" returned last week after having been gone for more than a year.
Reality shows often use the same rules. That's why limited-run series are a growing trend. One of ABC's biggest new projects, "Stephen King's Kingdom Hospital," will air a total of 13 weeks.
"They don't have to commit to it for nine months of the year," said Lloyd Braun, ABC entertainment chairman. "They don't have to commit to it for five years. They basically have a beginning, a middle and end in a determined period of time and they get to move on to something else."
The downside for networks is the lack of stability. A hit series is here today, gone tomorrow.
CBS, however, feels awfully secure knowing that "CSI: Crime Scene Investigation" will air virtually every week of the year.
ABRUPT SCHEDULE SHIFTS
NBC switched "The Apprentice" from Wednesday to Thursday after just one week, concerned that "American Idol" was making it impossible to compete. Then, when Donald Trump's boardroom reality show took off, NBC quickly scheduled reruns. And then CBS hurriedly put a rerun of "CSI" on against it one week to steal some audience.
You get the picture. Schedules stay in motion as executives search for every possible advantage. TV executives are also as competitive as athletes: CBS' Moonves loves to stick it to NBC's Zucker (notice the sly reference to NBC failure "Coupling" earlier?), and vice versa. That's partly why "CSI" was deployed to derail "The Apprentice."
Zucker is a big proponent of aggressive scheduling, arguing that the days of viewers forming habits around TV schedules are largely over.
But at TV Guide magazine, executive editor Steve Sonsky says viewers are bewildered. "We get letters like, why can't NBC make up its mind whether 'The Apprentice' is on Wednesday or Thursday night?"
Many executives figure that when the ratings improve as a result, that they've satisfied more people than they've alienated.
"I think it's very difficult for a viewer to know what's going on in television right now," Berman says. "But I also understand the competitive factors involved with the business."
For the most part, networks need to run a scripted show at least twice to recoup the costs of making it. But with dozens of other channels to choose from, viewers are increasingly rejecting second runs.
Some reruns score better in the ratings than others. Comedies generally do better than dramas. Dramas that tell a single story each week do better than those with a narrative thread.
So expect fewer narrative series to be repeated. ABC, for example, generally gives only one run to "NYPD Blue."
ABC is considering licensing some of their series to cable networks that will air the reruns instead. Networks are also borrowing another idea from HBO in trying insta-reruns, airing second runs less than a week after it's first shown.
Ever program your recorder for "Friends" or "American Idol" without realizing the network has tapped an extra 15 minutes onto the show - and the recorder doesn't pick it up?
The super-sized show, a phrase Zucker adapted for TV, is all about money. A few extra minutes of "Friends" means a few extra minutes of ads on television's most popular comedy.
More popular now is fiddling with starting and ending times of programs, doing anything possible to prevent viewers from using their remote controls.
One fascinating battleground is Thursday nights at 10 p.m. ET. CBS is well aware that many fans of "CSI," television's most popular show, switch networks when it's over to watch an old favorite, NBC's "ER."
So CBS frequently runs "CSI" a few minutes long. To complicate matters, NBC sometimes begins "ER" a minute or two before the hour.
Neither network wants to make it easy for a viewer to change channels. The question is whether there are repercussions to messing with the audience's viewing habits.
"There is a price you pay when you do that," Braun said. "Sometimes you evaluate it and it's worth the price."