NBC's new mid-season drama The Black Donnellys will premiere on Monday, March 5 (10-11 p.m. ET) -- following the hit drama Heroes (9-10 p.m. ET) - while the new comedy Andy Barker, P.I. , starring Andy Richter, will debut on Thursday, March 15 (9:30-10 p.m. ET), it was announced by Kevin Reilly, President, NBC Entertainment.

Studio 60 on the Sunset Strip (currently Mondays, 10-11 p.m. ET) will return later this season on a date to be determined. 30 Rock will return to its previous Thursday (9:30-10 p.m. ET) day and time with original episodes on April 19 after Andy Barker, P.I. completes its slate of episodes.

Academy Award winners Paul Haggis and Bobby Moresco (both for Crash) are the creators and executive producers of The Black Donnellys, a gritty new crime-drama series filmed in New York City and loosely based on Moresco's background.

The series follows the exploits of four young, working-class Irish-American brothers and their involvement in organized crime in New York City. The Donnelly brothers will do anything to protect each other against all odds.

The ensemble cast includes Kirk Acevedo, Thomas Guiry, Billy Lush, Keith Nobbs, Michael Stahl-David, Jonathan Tucker and Olivia Wilde. The pilot was directed by Haggis, who also wrote the Academy Award-winning Million Dollar Baby.

In the comedy Andy Barker, P.I. , Richter (Late Night with Conan O'Brien) re-teams with Conan O'Brien (series co-creator and executive producer). Richter portrays Andy Barker, an earnest, hard-working CPA who has succeeded at everything -- until his new accounting business fails to take off. But when he's mistaken for Lew Staziak (Harve Presnell, Fargo), the retired private detective who used to occupy his storefront office, Andy embraces the twist of fate and dives into his double life.

Andy's relentlessly supportive wife Jen (Clea Lewis, Ellen) isn't sold on this risky new venture, that is, until she notices a sudden boost in Andy's self-confidence. Andy's fellow strip mall neighbors -- Simon (Tony Hale, Arrested Development) and Wally (Marshall Manesh, Will & Grace) join him in the dicey investigations.