Due Date Due Date is a 2010 American comedy road film directed by Todd Phillips, co-written by Alan R. Cohen, Alan Freedland, and Adam Sztykiel, and starring Robert Downey, Jr. and Zach Galifianakis. Storyline Peter Highman (Robert Downey Jr.) will be a dad for the first time when his wife gives birth in five days. He intends to catch a flight home from Atlanta so he can be there for the delivery, but a chance encounter with aspiring actor Ethan Tremblay (Zach Galifianakis) throws a monkey wrench into his plans. Desperate to reach his wife before their baby is born, Peter's sanity is tested when he must take a road trip cross-country with dog-toting Ethan. Cast Zach Galifiankis as Ethan Trembley Robert Downey Jr. as Peter Highman About Ethan Tremblay Ethan Chase (known by the stage name of Ethan Tremblay ) is a fictional actor obsessed with Two and a Half Men who appeared in Due Date . He became an actor because of ...