So it sounds like "Mad Men" is coming back. We just don't know when.

Several trade publications, including Deadline.com and Variety, are reporting that AMC, Lionsgate and "Mad Men" creator Matthew Weiner are close to a deal for a fifth season of the show (UPDATE: And a sixth season as well.) The sides have been negotiating for months - back at the January TV critics press tour, AMC execs seemed confident the deal would be done soon - and now leaks from the various parties suggest it's actually going to happen, and soon.

But there's a long gap between getting a deal done - and putting Weiner and his writers back to work - and getting the show on the air, particularly since there's a complicated series of windows for when "Mad Men" might be able to debut.

Right now, "Breaking Bad" is tentatively returning in June, and "The Walking Dead" tentatively in late October. Given the late start, it's hard to imagine "Mad Men" being ready before fall at the earliest ("The Walking Dead" writing staff only got back to work a few weeks ago, again aiming for Halloween). I suppose AMC could try to pair its two highest-profile shows in the fall, perhaps using the huge "Walking Dead" audience to try to boost "Mad Men" from boutique hit to actual hit, but A)I imagine there's a large percentage of "Walking Dead" viewers who were drawn to it as a zombie drama rather than a quality drama, and B)It's usually not sound programming to use your biggest hit (and by far the biggest hit in your channel's history) as a lead-in to a show going into its fifth season. More likely, it seems, AMC would try a new show after "Dead," likely the Western "Hell on Wheels."

Of course, as AMC president Charlie Collier told me after that January press conference, AMC isn't married to Sundays, just because that's where they've put all their originals the last few years. "Mad Men" originally aired Thursdays at 10, and it's also possible that they could try it on another night, knowing that it has a fiercely loyal audience at this point that would follow it to Monday, or Tuesday, or even back to Thursday. Variety's story says that "Sources close to the situation say there's confidence at AMC that 'Mad Men' will be on the air at some point this year," and it would either have to air on another night to do that or piggyback on "Walking Dead."

But if AMC execs decide (as HBO once did, after briefly experimenting with airing some of its series on Mondays) that Sundays are the only night that makes business sense, and if they don't think there's value in putting Don Draper on after zombies - or if the negotiations continue to remain "close, but not quite close enough" for a little while longer - then I would not be shocked in the least to see the premiere put off until January 2012.

It sounds like we'll certainly have Don, Peggy, Joan and company back in our lives, which is good. But as happened on Weiner's old gig at "The Sopranos," it could be a while.