Where I work I get 6 weeks of vacation and 10 floating holidays. It's actually pretty difficult to use up that much vacation if you try to take it in big chunks, and I am sort of averse to travel (because a former job I had required so much that now I am sick of it even for personal "fun"). So now I take almost every Friday off or Monday. If you work it out with holidays you basically work 4 days a week. Since I have been doing this for several years now I have found that I am actually a lot more productive than when I work 5 days a week and take several weeks in a row off. For me, the 4 day work week makes me happier and I get more done.