Here's a look at some notable birthdays being celebrated today:

Merle Haggard
Age: 75
Occupation: Singer, Songwriter and Musician
Known For: Creating country's Bakersfield Sound along with his band the Strangers and Buck Owens, being part of the "outlaw country" movement, scores of No. 1 hits like 'Okie from Muskogee,' 'I Think I'll Just Stay Here and Drink' and 'Natural High,' and influencing countless other artists

Paul Rudd
Age: 43
Occupation: Actor
Known For: Being the adorkable star of films like 'Clueless,' 'Anchorman,' 'The 40-Year-Old Virgin,' and 'Knocked Up,' and playing Mike Hannigan, Phoebe's boyfriend and later husband, on 'Friends'

Billy Dee Williams
Age: 75
Occupation: Actor
Known For: His Emmy-nominated role as NFL star Gale Sayers in the TV movie 'Brian's Song,' playing the suave Lando Calrissian in 'The Empire Strikes Back' and 'Return of the Jedi,' roles in other films like 'Lady Sings the Blues,' 'Nighthawks' and 1989's 'Batman,' and guest-starring on a slew of television shows

John Ratzenberger
Age: 65
Occupation: Actor and Voiceover Artist
Known For: Playing know-it-all postal carrier Cliff Clavin on 'Cheers,' voicing at least one character in every Pixar movie to date, including Hamm the Piggy Bank in the 'Toy Story' series and Mack the truck in the 'Cars' franchise, and appearing as a contestant on the fourth season of 'Dancing with the Stars'

Zach Braff
Age: 37
Occupation: Actor, Writer and Director
Known For: His role as Dr. John Dorian on the sitcom 'Scrubs,' writing, directing and starring in 'Garden State,' and compiling its Grammy-winning soundtrack