Dax Shepard works on his relationship ''like a job''.

The 'Parenthood' actor feels it is important to work hard on his marriage to the 'Frozen' star and says they always have to make a point of scheduling time together, especially with their busy careers and lives.

He said: ''It's not effortless. We do couple's therapy. We work it like a job. Relationships aren't just perfect. We just commit to things. If I say, 'Hey, what are you doing Thursday?' It's never going to happen.

''But if I put something on the calendar ... it works out. But you do have to take it as seriously as you take your work commitments. It has to be scheduled and you have to prioritise it or it doesn't happen.''

The 42-year-old actor - who has Delta, two, and Lincoln, four, with Kristen - likes to do romantic things for his wife.

Asked about the most romantic thing he has done for Kristen, he added to People Now: ''We got into this really crazy one-upmanship of - so she was doing a movie in Alaska and I was shooting 'Parenthood' and I couldn't go and she was going away for a long time. But then my schedule changed and I didn't tell her, so I got the seat next to her on the airplane and then I sweet-talked the gate representative to let me on the plane early.

''So when she went to sit down, I was in her seat reading a newspaper and she kept going, 'Excuse me, sir. Excuse me, sir. I think you're in my seat.' And then she noticed those hands look familiar and then she started bawling when she saw that I was on the flight. And then so she did it to me on the way back.''