Letterman left "Late Night" in 1993 for Late Show with David Letterman (1993) on CBS when NBC give the "Tonight Show" to Jay Leno following the departure of Johnny Carson in 1992. However, NBC refused to allow Letterman to use elements that made the show famous such as "Larry 'Bud' Melman" or "The Top Ten List". NBC claimed those bits were their "intellectual property". "The Top Ten List" was renamed "Late Show Top Ten" and "Larry 'Bud' Melman" used his real name, Calvert DeForest.
The program ran four nights a week, Monday to Thursday, from the show's premiere in February 1982 until May 1987 with Friday Night (1983) airing in the 12:30 a.m. slot on Fridays with occasional Late Night specials and reruns. However, Friday shows were added in June 1987 since Friday Night Videos was cut from 90 minutes to 60 minutes.
In September 1991, with The Tonight Show Starring Johnny Carson (1962) being pushed back from 11:30 p.m. to 11:35 p.m., Late Night began starting at 12:35 a.m., at the request of NBC affiliates who wanted more advertising time for their profitable late newscasts.