Many of NBC's current shows aren't locks for next season, given low ratings, a new head of the network, perhaps a desire to make a clear break from the Jeff Zucker era. Only a handful of the network's series - notably "30 Rock," "The Biggest Loser" and a few other reality shows - already have been renewed for next season. But at the very least, we now know when the current (if not final) season for most NBC shows will be wrapping up.

In a press release put out today - which also noted that the hour-long 100th episode of "30 Rock" would air on April 21 - NBC announced the following season finale dates:

MONDAY, APRIL 4

“Harry’s Law” (10-11 p.m.)

FRIDAY, APRIL 8

“Who Do You Think You Are?” (8-9 p.m.)

TUESDAY, APRIL 19

“Parenthood” (10-11 p.m.)

SUNDAY, MAY 1

“America’s Next Great Restaurant” (8-9 p.m.)

THURSDAY, MAY 5

“Perfect Couples” (8:30-9 p.m.)

“30 Rock” (10-10:30 p.m.)

THURSDAY, MAY 12

“Community” (hour-long episode from 8-9 p.m.)

“Outsourced” (10:30-11 p.m.)

MONDAY, MAY 16

“Chuck” (8-9 p.m.)

WEDNESDAY, MAY 18

“Law & Order: Special Victims Unit” (10-11 p.m.)

THURSDAY, MAY 19

“The Office” (one-hour finale from 9-10 p.m.)

“Parks and Recreation” (hour-long finale from 10-11 p.m.)

MAY 21

“Saturday Night Live” (11:30 p.m.-1 a.m.)

SUNDAY, MAY 22

“The Celebrity Apprentice” (9-11 p.m.)

MONDAY, MAY 23

“The Event” (9-10 p.m.)

TUESDAY, MAY 24

“The Biggest Loser” (9-11 p.m.)