Charlie Day lightens up in ‘Going the Distance’

Like many comic actors, when he doesn’t have to be “on,” Charlie Day can be almost unrecognizably normal.

“People have to remember that we write and produce that television show, which is a pretty heavy workload,” says the calm, bearded star of “It’s Always Sunny in Philadelphia” and costar of the new romantic comedy “Going the Distance.” “So when I’m not playing a character that is huffing glue and eating cat food and sleeping in my long underwear with Danny DeVito [as on the show], I’m a relatively hard-working, serious guy.”

Battered toys on the patio betray a fond indulgence for his energetic 6-year-old rat terrier, Arthur. Inside the house Day shares with wife Mary Elizabeth Ellis, who plays the waitress on “Always Sunny,” two guitars and a ukulele in the corners of the cozy living room reflect the musical nature of his family (his parents were both music teachers in Middletown, R.I.): “If people know Rhode Island, they know the Newport area that’s famous for its beaches and mansions. Then the town next to it is Middletown, where the people are who are employed by the mansion owners.”

At the urging of a professor, he found his way as a young man to the Williamstown Theatre Festival in Massachusetts.

“The summer before, I’d been painting houses and the summer before that, I was a janitor,” Day says. “The outcomes were, try the summer theater festival or hang out with my friends in Rhode Island and try to make a living. So I opted for the festival.”

He got a part in the 1997 Williamstown production of “Dead End” as Scott Wolf’s nemesis in a cast that included Campbell Scott and Hope Davis, but he was too intimidated to cut loose in rehearsals.

“A few days in, I realized, ‘They’re going to get rid of me if I don’t do something aggressive,’ so I decided I’d just get right up in Scott Wolf’s face and really pick a fight with a touch of humor behind it. The director pulled me aside and I was terrified: ‘Oh, my God, this is it, I’m done.’ And he said to me, ‘Have you ever considered doing this for a living?’ So it was a good lesson: You’ve got to sink or swim,” he says.

Fast-forward to 2010 and the sometimes raunchy little show Day and some friends launched in 2005 has blossomed into an FX channel stalwart with six seasons (so far) of “It’s Always Sunny in Philadelphia” — or per the tagline, “Seinfeld on crack.” Geoff LaTulippe and Nanette Burstein, “Going the Distance’s” writer and director, respectively, were fans of the show about friends and family being awful to each other, and brought the 34-year-old Day in for an equally outré — but distinctly sweeter — role. “Distance” does feature anatomical jokes and one scene with Day’s character, Dan, on the toilet, but the actor emphasizes how supportive Dan is of his buddy Garrett ( Justin Long) as Garrett struggles with a cross-country romance with Erin ( Drew Barrymore).

“The characters genuinely care about each other,” he says. “You might be teasing your friend, but if he says, ‘It’s not going to work out, this girl doesn’t like me,’ then the teasing stops and the seriousness begins. That’s when Dan goes in for a hug. But then the other character calls him out for the hug, and we’re back.”

The biggest adjustment from small to big screen, he says, was giving up control.

“I’m used to doing stuff on Sunday and knowing it’ll be in the final product because we’re in the editing room,” Day says, while noting his gratitude for how collaborative Burstein’s set was.

“The whole scene with me on the toilet, we reworked that to make it funny without being totally disgusting. My character is earnestly trying to connect with Garrett, who has admitted he’s in love with this girl, and Dan’s a romantic. So trying to have that conversation is how we were able to make it funny instead of just gross.”