WPHT announced that it has extended legendary broadcaster Sid Mark's contract just in time for Frank Sinatra's 100th birthday. Mark has been playing the sounds of Sinatra on the radio since he was on WHAT in 1959, and currently hosts "Sunday with Sinatra" on WPHT from 9 a.m. to 1 p.m.

Sinatra would have turned 100 on Saturday. To celebrate, Mark and WPHT team up for a special "Saturday with Sinatra" from 8 to 11 p.m. The show will include special birthday shoutouts, dedications and content that Mark has never played on the radio.

No word yet on how long Mark's contract has been extended, although in a statement, Mark said he was looking forward to his 60th anniversary playing Sinatra on the air.

Last month, Michael Smerconish declared that "In Philly, Sinatra means Sid Mark."

In today's Daily News, Ed Barkowitz details how Mark accidentally became Sinatra's biggest radio booster:

He was a deejay working the graveyard shift for WHAT in 1956 when a colleague failed to show up. With the extra airtime, Mark played a full hour of Sinatra. He's been doing it now for 59 years.

Mark's personal relationship with Sinatra, developed over 40 years, has always made "Sunday with Sinatra" a unique show. As Barkowitz relays, Sinatra counted Mark as one of his closest pals: "I've had maybe four or five [friends] in my career, people who've stayed with me when things were dark; didn't change at all when everything else changed," Sinatra told aSpectrum crowd. "That's the kind of man he is. I love him, and I say that publicly. I love him. He's one of the best friends I've had in my life."