In Depth

Leno's NBC Era to End in Late May, Early June; Tune in Monday for Details

NBC on Monday will announce the exact timetable for Jay Leno to hand over the host's chair on "The Tonight Show" to Conan O'Brien, several people with knowledge of the plan said over the weekend.

It's very likely Mr. Leno will host his final "Tonight Show" in late May or early June, according to two people familiar with the plan. Mr. O'Brien will take over on the Monday following Mr. Leno's last broadcast.

The exact dates of the handover are being guarded like a state secret, since NBC brass don't want to anger members of the media who have assembled in Beverly Hills for the Television Critics Association press tour, site of the expected announcement.

If NBC executives want to go the sentimental—or, perhaps, superstitious—route, Mr. Leno and Mr. O'Brien could duplicate the Carson-Leno playbook exactly.

Mr. Carson's final "Tonight Show" aired on May 22, 1992; Mr. Leno took control of the franchise May 25. As it happens, May 22, 2009 falls on a Friday, while May 25, 2009 is a Monday.

The downside to that plan: May 25 is Memorial Day, and NBC might not want to kick off "The Tonight Show with Conan O'Brien" on a holiday. If so, NBC might push Mr. O'Brien's bow until Monday, June 1.

The transition to NBC's new late-night lineup will actually begin this fall.

That's when Jimmy Fallon—who's been tapped to replace Mr. O'Brien as the host of NBC's "Late Night"—will launch his show on the Internet as a series of webcasts. Executive producer Lorne Michaels announced the strategy Sunday, saying Mr. Fallon would webcast for "five or six months" before taking to the airwaves.

Mr. O'Brien is expected to host his final original episode of "Late Night" not long after the first of the year. He will take several months off the air in order to move his staff to Burbank.

NBC will air repeats of "Late Night" until the spring—most likely March, one NBC insider said—when Mr. Fallon is expected to take over at 12:37 a.m. NBC wants to give Mr. Fallon a moment in the spotlight before Mr. O'Brien takes over "Tonight."

One person familiar with the transition plans said that while the dates of Mr. O'Brien's first "Tonight" telecast and Mr. Leno's final bow will be revealed Monday, the network may not yet be ready to announce an exact premiere date for Mr. Fallon.

(Editor: Baumann)