NBC will usher in the 2008-09 season with a big, splashy return for "Heroes," which will end a 9 1/2-month absence from the air in September.

The network is turning over its entire prime-time slate on Monday, Sept. 22 to the show, starting with an hour-long clip show to refresh viewers' memories on what's happened so far and leading into a two-hour season premiere. It leads a fairly traditional rollout for NBC, which will debut most of its shows between then and early October.

NBC has also made a few tweaks to the looking-way-ahead schedules it presented to advertisers and the press in April. The biggest change is that the new comedy "Kath & Kim" will join the network's Thursday comedy block on Oct. 9; it had been scheduled for Tuesday nights following "The Biggest Loser," which will expand to two hours.

That change pushes a series of "Saturday Night Live" prime-time election specials from 9:30 to 8:30 p.m. Thursdays in October. The third season of "30 Rock" will hold off until Oct. 30.

Additionally, the unscripted series "America's Toughest Jobs" moves up from summer '09 to the fall, premiering Friday, Sept. 12. It will air at 8 p.m. ET for several weeks, then move to 9 p.m. in October after the premiere of "Crusoe." ("Deal or No Deal" will move off the night when that happens.)

The rollout of the network's three dramas will be staggered a little. The updated "Knight Rider" will debut Wednesday, Sept. 24, while "My Own Worst Enemy" will follow "Heroes" on Monday, Sept. 29. "Crusoe" has its two-hour premiere on Friday, Oct. 17.

NBC's premiere schedule is as follows (all times Eastern, new shows in bold):

Friday, Sept. 12

8 p.m. "America's Toughest Jobs" (moves to 9 p.m. Oct. 24)

Monday, Sept. 22

8 p.m. "Heroes" clip show
9 p.m. "Heroes (two hours)

Tuesday, Sept. 23

10 p.m. "Law & Order: SVU"

Wednesday, Sept. 24

8 p.m. "Knight Rider"
10 pm. "Lipstick Jungle" (new timeslot)

Thursday, Sept. 25

8 p.m. "My Name Is Earl" (one hour)
9 p.m. "The Office" (one hour)
10 p.m. "ER"

Monday, Sept. 29

8 p.m. "Chuck"
10 p.m. "My Own Worst Enemy"

Friday, Oct. 3

10 p.m. "Life" (new timeslot)

Thursday, Oct. 9

9:30 p.m. "Kath & Kim"

Friday, Oct. 17

8 p.m. "Crusoe" (two hours)

Thursday, Oct. 30

8:30 p.m. "30 Rock"