A look ahead at Thursdays lineups

A night dominated by convention coverage seems as good a time as any to glance ahead to the upcoming season, and to ways that the network’s Thursday night will be changing. And staying the same.

CBS, the most popular among the networks, tampers only slightly with its lineup. Last year’s reboot of “Two and a Half Men” (7:30 p.m.) moves to Thursdays permanently. “The Big Bang Theory” (7 p.m.) and “Person of Interest” (8 p.m.) stay where they are, and “The Mentalist” moves to Sundays. It’s to be replaced by the new series “Elementary” (9 p.m.), a 21st-century update of Sherlock Holmes, starring Jonny Lee Miller as the detective and Lucy Liu as Dr. Watson.

NBC’s Thursday night offers at least two of its comedies a valedictory victory lap — or victory limp, given their declining ratings. “The Office” (8 p.m.) and “30 Rock” (7 p.m.) enter their final seasons. They’ll share the schedule with “Parks and Recreation” (8:30 p.m.), which, like “30 Rock,” has enjoyed increasing critical respect as it has evolved. Thursdays also include “Up All Night” (7:30 p.m.), starring Will Arnett, who is married to “Parks” star Amy Poehler. The largely unwatched “Rock Center With Brian Williams” (9 p.m.) will return.

Fox is counting on singing talent, real and scripted, to carry the night. Look for “The X Factor” (7 p.m.) in the fall and “American Idol” (7 p.m.) in the spring. “Glee” (8 p.m.) follows with its first season since the original gang graduated from William McKinley High.

The CW promises to keep its Thursdays supernatural with the return of “The Vampire Diaries” (7 p.m.), followed by the new adaptation of “Beauty and the Beast” (8 p.m.).

ABC will take the biggest gamble of the night with “Last Resort” (7 p.m.), an adventure fantasy written by Shawn Ryan (“The Shield”) about the crew of a super-secret submarine, branded as an enemy of the state after refusing to carry out a nuclear strike. The crew members take refuge on an exotic island while trying to clear their names. Standby “Grey’s Anatomy” (8 p.m.) follows, while “Scandal” (9 p.m.) was picked up after a brief run last spring. Both shows were created by Shonda Rhimes.

• Coverage of the Republican National Convention (6 p.m., CNN, Current; 7 p.m., PBS, Fox News, MSNBC, Bloomberg; 8:30 p.m., BET; and 9 p.m., ABC, CBS and NBC) continues. Tonight’s highlights include nominee Mitt Romney’s acceptance speech.