@Lioness94 - the way he put it, he is some kind of freelancer. There are all kinds of jobs for freelancers - programming, design, art, animation, call center... When it comes to offline jobs, I know civilian sailors work like that.
Or maybe he works for a company that works on a similar approach and doesn't try too hard to fill all of its time. I suspect construction work is like that - it's not every day that somebody has the land and money to build a house.