Charlie Day’s love of romantic comedies started long before he was cast to lead one.

The Manhattan-born “It’s Always Sunny in Philadelphia” star couldn’t wait to tackle the genre when his new movie, “I Want You Back,” came along, citing an affinity for classics like “Sleepless in Seattle” and “When Harry Met Sally.”

“I really love Tom Hanks and Billy Crystal,” Day said. “To get to see them be leading men in movies, but also leading men in an attainable and familiar way — they have this sort of everyman feel. I was hopeful that I’d one day get an opportunity to do my version of that.”

Day’s opportunity arose with “I Want You Back,” which also stars Jenny Slate and follows two strangers who get dumped during the same weekend and agree to help each other win back their relationships.

Chaos ensues as Day’s Peter and Slate’s Emma carry out their schemes. The film is available on Amazon Prime Video.

“This wasn’t a movie where these guys push down a magic toaster and they are living a different life. It was just a movie, really, about people,” Day said.

“It was exciting to play some of the more emotional and grounded aspects of the story, and then to see the funny sort of set pieces that I’ve been given the opportunity to do in the past,” he said. “I was happy that those were there, but I was really looking forward to just the more human, conversational aspects of the movie.”

Day, 45, rose to fame playing the eccentric Charlie Kelly on the FX sitcom “It’s Always Sunny in Philadelphia,” and also starred in comedy films including “Horrible Bosses” and “Fist Fight.”

Day said he didn’t have a specific genre in mind when he set out to become an actor, but relishes doing comedy and enjoyed playing a different type of character in “I Want You Back.”

“I just thought, ‘Well, I have to work, and if I can work and make a living at this, then I can call myself an actor and it will be fulfilling.’ I’ve been fortunate enough to get to do that,” Day said. “Whatever presented itself to me, I would’ve done. If drama popped up first and it was only dramatic roles and that’s the way people wanted to see me, I would’ve done that. But fortunately comedy came up, and I really also enjoy comedy.”

Day appreciates the different journeys the characters take in “I Want You Back,” and believes the movie features a message of self-discovery.

“You have to get right with yourself before you can get right with others,” Day said. “What’s great in this film is that the characters, they really have to come to terms with who they are as people and their behavior, and realize that they need to start taking care of themselves.”

The actor, who is married to “It’s Always Sunny” co-star Mary Elizabeth Ellis, says the new movie also showcases the challenges of dating in the social media era.

“I really sympathize for people out there in the dating world,” Day said with a laugh. “But it’s also a hopeful movie saying that love could be out there if you’re looking in the right places.”