NBC has unveiled a raft of schedule changes and new series premieres for its mid-season schedule.

A new week-long run of Deal or No Deal will start earlier than expected on February 27. Several existing shows will move around on the schedule, with Law and Order sliding back an hour to a 9pm slot on Wednesdays, Dateline NBC moving from Fridays to Saturdays, and Las Vegas shifting to Fridays.

Among the other premieres scheduled for February and March, Donald Trump's Apprentice starts up again on February 27, Conviction - a new series from Law and Order creator Dick Wolf - starts on Friday, March 3, and Heist starts on Wednesday, March 22.

Teachers, a new comedy starring Justin Bartha alongside Coupling's Sarah Alexander, will premiere on Thursday, April 6, replacing The Office when it ends its current season.

"We are not going to slip quietly into spring," said Kevin Reilly, NBC entertainment president, at the Television Critics Association Press Tour. "With these exciting new shows in our re-configured schedule, we will be very competitive -- and given the promotional momentum of the Olympics, we can give these promising shows the launch they deserve."