For more than 20 years, NBC owned Thursday nights. No matter what else was ailing the Peacock, the network could count on an orderly transfer of power from "The Cosby Show" to "Cheers," from "Seinfeld" to "Friends," from "L.A. Law" to "ER."

Now, Thursdays are just one more problem in an ever-mounting pile of them, with the network consistently coming in fourth on a night it used to dominate, and many weeks finishing in a dead heat with Univision — which may explain why the night is an afterthought in the fall schedule that NBC entertainment president Robert Greenblatt announced on Sunday afternoon.

All six of the comedies that aired on Thursday this season — "The Office," "30 Rock," "Community," "Parks and Recreation," "Up All Night" and "Whitney" — will be returning next season, albeit not all on Thursdays. ("Whitney" and "Community" get banished to Fridays, which is a fate better than death, but only just.)  But where once upon a time NBC might have tried to slot in its highest-profile new comedy — say, "Go On," featuring former Must-See TV star Matthew Perry — on Thursday at 9:30 after "The Office," now all of NBC's new sitcoms will be airing on Tuesdays and Wednesdays. And that 10 p.m. timeslot that was once unassailable and this year rapidly killed "Prime Suspect," "The Firm" and "Awake" will now go to "Rock Center with Brian Williams," the newsmagazine that NBC spent much of this spring trying to hide in out-of-the-way spots on the schedule due to its meager ratings.

This is NBC running up the white flag on Thursdays and deciding to make its stand on firmer ground earlier in the week.

"One of the reasons that (the schedule) laid out the way that it did is that I'm just determined to build momentum from night to night, which is something that has eluded us in recent years," Greenblatt explained on a press conference call. With football on Sunday night and "The Voice" (which will air in fall and spring next season) on Mondays and Tuesdays, they have a good promotional base early in the week. "To get that momentum going from night to night, we really focused on Tuesday and Wednesday, and the further you get from the Sunday/Monday, the harder it is to keep the momentum going. Knowing that we can't do everything at once, we really focused on that."

Greenblatt also acknowledged that as much as critics love the Thursday comedies, the mass audience hasn't really been there for any (save "The Office," and it was way down this season without Steve Carell), and he hoped that the new comedies would be "broader and more accessible, and could garner a larger audience."

Analysis of the schedule night-by-night:

SUNDAY: In the fall, this is easy: "Sunday Night Football" this season was the highest-rated show on television, beating out even "American Idol." In the spring, they'll patch things together with "Dateline" at 7, the low-rated (but well-supported by product integration) "Fashion Star" at 8, "Celebrity Apprentice" reduced to an hour (until something else fails) at 9, and "Do No Harm" (a Jekyll & Hyde drama starring Steven Pasquale from "Rescue Me") at 10.

MONDAY: Even though "The Voice" has fallen off significantly in the ratings throughout its second season, and even though many previous TV phenomenons have been killed through early overexposure (see "Who Wants To Be a Millionaire"), Greenblatt isn't concerned about airing two editions of it next season. He pointed out that "Dancing with the Stars" and "Survivor" have done that for years, and argued that even FOX is doing it now with "American Idol," given how similar "The X Factor" is to it. In an attempt to keep viewers interested once the show moves past its popular audition rounds, Greenblatt said the plan is to incorporate the rotating judges' chairs into later rounds, but he was "not at liberty to say" how. (Presumably, that authority rests not with the president of the network, but with Cee Lo's cat.)

"Smash," which had the post-"Voice" timeslot this spring, will be part of NBC's huge mid-season bench, returning at a date and time TBA with 15-18 episodes, and new showrunner Josh Safran ("Gossip Girl"), whom Greenblatt said would help the show best by "shoring up the serialized storytelling." In the meantime, that 10 p.m. timeslot goes to "Revolution," a sci-fi drama from J.J. Abrams and "Supernatural" producer Eric Kripke that takes place in a world 15 years after all modern sources of energy have disappeared.

"Broad" was Greenblatt's word of the day, and he said the goal is to pair "The Voice" with "the broadest show you possibly can," even as he acknowledged that "Smash" was never that, and went Mondays at 10 because he liked the show and thought it needed the help.

TUESDAY: "The Voice" results show is at 8, and "Parenthood" is back at 10. In between are "Go On," starring Perry as a recently-widowed sportscaster returning to work; and "The New Normal," from "Glee" producers Ryan Murphy and Ali Adler, about a gay couple (Andrew Rannells and Justin Bartha) who hire a surrogate (Georgia King) to help them start a family.

Under an old regime, "Go On" almost certainly would have gotten the old "Friends" timeslot Thursdays at 8. Instead, Greenblatt tries to use "The Voice" to give it a boost, even though FOX's many failed attempts to use "Idol" to launch comedies suggests there's not a lot of overlap between reality competition audiences and sitcom audiences.

WEDNESDAY: NBC didn't do particularly well airing new comedies in the 8 o'clock hour here this season, although "Up All Night" and "Whitney" (which both also did time on Thursday) were renewed by the skin of their teeth. But with Greenblatt trying to launch as many comedies as possible — NBC will have four different comedy blocs next season — we get Justin Kirk from "Weeds" as a misanthropic veterinarian in "Animal Practice" at 8, and the buddy/family sitcom "Guys with Kids" (starring Anthony Anderson, Jesse Bradford Jamie Lynn Sigler from "The Sopranos" and another NBC Thursday alum, Tempestt Bledsoe from "The Cosby Show") at 8:30. At 9, "Law & Order: SVU" remains the last piece of the franchise standing, and it leads into another Dick Wolf series "Chicago Fire," an ensemble fireman drama headed by Jesse Spencer from "House."

THURSDAY: The line-up for the fall is "30 Rock" at 8, "Up All Night" at 8:30, "The Office" at 9, "Parks and Recreation" at 9:30 and "Rock Center" at 10. Though there were reports last week that "30 Rock" had been renewed for a final season — and that "The Office" (and possibly "Community" would be given the same designation — Greenblatt insisted that none of those shows will automatically end this season. All of "The Office" cast is expected back in some form, other than Mindy Kaling (whose sitcom got picked up by FOX). Though a Dwight spin-off is in the works, it hasn't technically been picked up yet, whereas there are already three new sitcoms on the bench in "Save Me" (Anne Heche becomes a prophet after a near-death experience), "1600 Penn" (Bill Pullman and Jenna Elfman as the President and First Lady) and "Next Caller" (Dane Cook as a satellite radio shock jock).

FRIDAY: Even though Greenblatt says none of his comedies are entering the season with the assumption that it will be their last, it's hard to imagine either "Whitney" (at 8) or "Community" (at 8:30) surviving in a death slot. On the other hand, "Community" was barely renewed to begin with, given its ratings (and the fact that, unlike "30 Rock" or "Up All Night," NBC doesn't produce it). Four seasons at Greendale Community College at a minimum seems miraculous, frankly. Of more concern than the timeslot, in fact, is the possibility that creator Dan Harmon (whose contract is up at the moment) might not return next season. Greenblatt acknowledged that the show might have to move on without its chief creative voice.

"I expect Dan's voice to be a part of the show somehow," Greenblatt suggested. "I'm not sure exactly if that means him running it day to day or consulting on it. I haven't been part of those conversations because we've been in scheduling meetings for four or five days."

Greenblatt also said he's trying the two sitcoms out at 8 in hopes that a scripted lead-in might help "Grimm," which returns at 9, followed by "Dateline."

SATURDAY: Repeats. NBC, like most of the other networks, long ago gave up on this night.

In addition to the series mentioned above, NBC will also welcome back "The Biggest Loser" and "Betty White's Off Their Rockers" at mid-season, along with new shows "Hannibal" (the early careers of Hannibal Lecter and FBI agent Will Graham), "Infamous" ("Revenge"-esque soap about a cop investigating the death of her wealthy friend) and reality series "Stars Earn Stripes," "Howie Mandel's White Elephant," "Ready for Love" and "Surprise with Jenny McCarthy."

Alan Sepinwall may be reached at sepinwall@hitfix.com