What seemed so far off in the future has now been given a date. Jay Leno‘s departure from The Tonight Show will happen on May 29, 2009.

This calendar announcement was announced earlier Monday by NBC. The news ended any speculation that the network might chicken out and keep the ratings winner in place a bit longer. Also solidifying the decision made years ago was the date chosen for Conan O’Brien‘s time shift: June 1.

While the Peacock network would undoubtedly love to keep Leno around in some capacity (his old employers will still be paying him through 2009), it’s highly unlikely the exiting host would stick around. Since CBS’ late-night programming slots are already full, there’s been increased speculation lately that Jay will eventually move over to ABC. (FOX’s horrible history with talk shows doesn’t really make it an attractive option.)

If the channel change happens, Jay’s presence would most likely mean the cancellation of Nightline and force an adjustment for Jimmy Kimmel. While some believe this possibility would be a slap in Kimmel’s face, others argue that he would benefit from a post-Leno slot.

Until the big switchover next year, there will be one more finale to take note of. Sometime after the new year, O’Brien will mark the end of Late Night with Conan O’Brien. Repeats of his show will then continue to air while the host preps for his new gig. Jimmy Fallon will then assume his new 12:30 a.m. post sometime in March or April. Leading up to the premiere, the former SNL-er will air webisode versions of his show in order to get his feet wet.