David Letterman's 34 year reign as a late night talk-show host, which began in 1982 on NBC's 'Late Night,' is coming to an end.

The 66 year-old longtime 'Late Show' emcee announced his retirement plans on Thursday night (April 3rd).

While addressing the viewers and in studio audience of CBS's 'Late Show with David Letterman', which he has been hosting for the past 21 years, Letterman thanked everyone for their support over the years.

"I just want to reiterate my thanks for the support from the network, all of the people who have worked here, all of the people in the theatre, all the people on the staff, everybody at home, thank you very much," he told the audience.

In a preview of Friday night's episode Letterman explains why he has chosen to step down at this time.

"A couple of days ago, Jane, a lovely woman who does my makeup every night-and you think you got a lousy job," Letterman jokingly told Paul Shaffer, the show's musical director. "She says to me, 'Dave, there's really nothing more I can do. I said, 'OK, fair enough.'"

The comedian also joked about what his future plans will hold, saying, "A year from now, I'll be on a beach with a metal detector!"

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But not everyone has took this news well, Alec Baldwin has set up a campaign on Twitter, urging fans to sign an online petition in order to persuade Letterman to stay with the television network.

"Maybe it's futile, but here goes... Letterman cannot retire. Just... just.... no. Send him this: #DontGoDave," he wrote.

'The Late Show With David Letterman' airs tonight at 11:35 p.m. on CBS.

Watch a preview clip of tonight's epsiode of the 'Late Show' below