 The show's start time was delayed by five minutes to allow NBC affiliates to include more commercials during their local newscasts.In an onscreen eulogy to Carson in 2005, David Letterman said that every talk show host owes his livelihood to Johnny Carson during his "Tonight Show" run.In 1979, when Fred Silverman was the head of NBC, Carson took the network to court, claiming that he had been a free-agent since April of that year because his most recent contract had been signed in 1972.