Anyone who has seen It's Always Sunny in Philadelphia even once knows Charlie Day. His character on the show, also named Charlie, is an unforgettable combination of vulnerability, rage and abject stupidity, and virtually every episode includes at least one or two choice "Charlie moments" in which Day offers an observation, idea or even just a shriek or two that is idiotically, irresistibly hilarious. This week marks Day's first major opportunity since Sunny started to bring his Charlie-style charm to the big screen, as he plays Dan, a predictably dim-witted buddy to Justin Long in the romantic comedy Going the Distance.

Cinematical sat down with Day at the recent Los Angeles press day for Going the Distance. In addition to talking about the shades of difference between Charlie and Dan, Day talked about maintaining a balance between characters that are empathetic and just plain idiotic, and examined the challenges of expanding his repertoire to include a larger variety of roles both in films and on television.