Years ago, I had a job where I had a four day week. (Actually four days a week every week, and an extra half day one week in three.) The trouble was, the extra couple of hours per day wore me down; after four days on, I needed an extra day just to get over the cumulative fatigue before I could enjoy the weekend.

The best single thing you can do to reduce working fatigue is to minimize your commuting time. If you commute an hour each way to work, then over a five day week, you've racked up an extra 10 hours -- not to mention the extra expense, and the aggravation periodically inflicted by traffic jams or public transport problems -- and the worst part of it is that it's mostly dead time. (I'll make an exception for commuting to work on foot or by bicycle, as part of an exercise regime.)

I think I have to recuperate on Saturdays now, too.

But yeah, I commute for 3h a day and it sucks. Haven't thought up a good solution yet, since I really don't like the city where I work.

I'm in the same situation. I'd kill for a four-day week. My commute is approximately 2 hours door-to-door each way, assuming that the mass transit system doesn't suffer any delays.

Actually, it does talk about squeezing a whole week's work into 4 days, so it's probably 4 10-hour days as well.

I've considered it, but I know my productivity sags at the 8 hour mark as it is, so I don't think it's a good fit for me or the company.

Actually, I wonder at which point you guys notice that your productivity drops. Very often my productivity drops noticeably after 7 hours, already, but it can come back in the evening.

Also, it often drops after lunch, but this also depends on when we have lunch. It's significantly worse if we have lunch around 12:00 than around 13:30-14:00. Our research group loves to go at 11:30 (!!!) which destroys the whole day for me, so a few of us have just stopped eating together with them.

Update: I've added a poll: http://news.ycombinator.com/item?id=2052007

I telecommute as well and basically have the first six hours of everyday by myself, so I feel very productive during that time. After lunch it drops some, but luckily that is also when meetings are so I feel it doesn't matter as much. If I still have time left and don't feel very productive (which happens maybe one day a week, sometimes more though) I usually have some work that doesn't require much mental effort (like administrative or light maintenance) and work on that. If I couldn't define my schedule like this it would probably be harder.

"Seventy-five percent of Dutch women now work part time, compared to 41 percent in other European Union countries and 23 percent in the United States"

"Twenty-three percent of Dutch men have reduced hours, compared to 10 percent across the European Union and in the United States; another nine percent work a full week in four days."

Well, I think a 36-hour work week is the norm in NL, so it's 4 9-hour days.

I spend about 11 hours in office, 5 days a week. So I would rather prefer 4 working days,10 hours each anyway!

There is no reason to believe that the work done per time unit remains the same when the length of work day varies.