Jay Leno will return to his old 11:35 p.m. time slot, NBC says, ending the comedian’s prime-time experiment. NBC execs say Conan O’Brien and Jimmy Fallon will be pushed back half an hour, though it’s not a done deal. Leno’s prime-time show will end Feb. 12, at the start of the Winter Olympics. Leno’s show performed well enough for the network, but did not meet the needs of NBC affiliates.