The 1999-2000 TV season is upon us.

Five shows debut this week, starting tonight with UPN's "Grown Ups"--a new sitcom starring the grown-up-but-still-cute Jaleel "Urkel" White--and "Moesha." On Thursday, UPN is debuting the second-most-talked-about new series of the season, "WWF Smackdown." That early launch was scheduled because the World Wrestling Federation--which has a major financial stake in UPN's two-hour weekly program--promised to promote the heck out of it last night during its pay-per-view wrestling event featuring Jesse "The Governor" Ventura.

The new season doesn't officially start until the week of Sept. 20. But Fox and UPN will try to get in early, figuring they'll fare better in a field of reruns than against original competition.

Fox, for instance, will debut the season's most talked about new show, the Hollywood spoof "Action," on Sept. 16. That's four days after Fox broadcasts the Primetime Emmy Awards. And by the time you've sat through three hours of the trophy show to find out whether HBO's "The Sopranos" becomes the first cable program ever to win the Emmy for best drama series, expect to have seen a whole slew of "Action" promos.

In addition to some of the new season's earliest debuts, Fox also has the latest. In fact, the new rich-kids-from-Hell drama, "Manchester Prep," and the new junior's-a-genius sitcom, "Malcolm in the Middle," are debuting so late they don't even have launch dates yet. They're not even really fall launches. "Manchester Prep" is supposed to debut sometime in December and "Malcolm" sometime in January. You'll see several midseason series come--and maybe even go--before you get your first glimpse of either of these two new Fox shows. Fox never intended to debut "Malcolm"--a 7 p.m. Sunday show--in the fall, when the football season is in full rage. Come on, a half-hour sitcom in that time slot in the fall? How many times has Fox not had a football overrun Sundays that ate up most of the 7 p.m. half-hour? "Malcolm" would've seen the light of day, oh, maybe twice during football season if it had actually launched in September. But Fox pretended "Malcolm" was on its schedule back in May--when advertisers cough up billions to buy ad time in the fall slate--because the network knew the sitcom would command a higher rate than something called "Filler Stuff Until the End of Football Season."

WB is split down the middle. About half of its series debut during the so-called Premiere Week and half do so later. Some of its late starts are strategic; others are born of necessity. For instance, WB's new animated half-hour show, "Mission Hill" (formerly known as "The Downtowners"), was originally supposed to get a "preview" on Tuesday, Sept. 21, and then move to its regular Friday 9 p.m. slot three days later. Now, the network says, it'll still air the first episode on the 21st, but you won't see the show again until Oct. 8. A WB source says execs wanted to have more episodes in the can so they could mix them up. Translation: Episode No. 2 didn't turn out great, so they'd like to make it episode No. 4 or 5 instead.

And for the first time in many years, the Big Three networks--ABC, CBS and NBC--are actually airing the first episodes of almost all their prime-time series during Premiere Week and in their designated time slots--a concept so retro it's revolutionary.

Yes, after years of indulging themselves at Club Meddle, the Big Three schedulers have taken the slow boat back to reality: Premiere Week is called Premiere Week because that's the week when viewers expect the shows to premiere. They've decided that telling viewers that a show will debut Tuesday at 8:30 p.m. means people will expect the second episode at the same time instead of Sunday at 7:30 p.m.

During their dark days at Club Meddle, scheduling suits insisted that all this premiere hanky-panky was better for the shows, better for viewers. They called it "stunting." Stunting covered a host of sins including: debuting a show outside Premiere Week; previewing a new show in the network's most fertile time slot in hopes viewers would watch it, like it, and follow it to its regular time period; "double pumping" a new show in several places on the schedule in hopes more viewers would sample it on two different nights.

Instead, a lot of viewers got fed up trying to track down a new show and moved on. "The burnout factor," CBS scheduling chief Kelly Kahl calls it.

Early and late launches may bring on the same viewer frustration, suggests NBC's scheduling guru, Preston Beckman. "We've done the research, and there's no evidence that an early premiere results in a hit show and no evidence that a late premiere results in a hit. Then why do it, other than to make announcements," he said.

Good old Premiere Week may turn out to be the most effective place to launch a new series, despite the crowding, Kahl says. In an age of so much TV clutter, promos for nine new shows, all of which deliver the same message--"Catch It, Premiere Week on CBS"--collectively may have the most impact, he says.

Which is not to say the schedulers are refraining altogether from their old ways. NBC, for instance, will give John Wells's new drama series, "Third Watch," its initial broadcast at Thursday 10 p.m. during Premiere Week, in hopes of snagging some viewers who tuned in expecting to see the first original episode of "ER" in months. The same thinking has CBS giving new touchy-feely chick drama "Judging Amy" a test run in "Touched by an Angel's" Sunday 8 p.m. time slot before it settles into its regular Tuesday 10 p.m. berth.

Old habits die hard.