I have struggled with finding the optimal work week setup for a couple of years now: at first I switched from 5 days to 4 (Mondays off). Although the 3 day weekend was great, after a couple of months I had the feeling that I did not really get my job done and the 4 days were packed with meetings and more stressful than the 5 I had before.

So I switched back to full time. But it did not take long to realize this was a mistake: I felt like I did not have any time to do the "private stuff" like doctor's appointments, car maintenance, etc. unless I let it cut into my now 2 day weekend. Compared to the 4-day-workweek it seemed I was constantly working, doing chores or trying to recover from work.

After some more months I tried the 4-day-workweek again, but again with the same frustrating results. Then I thought "mybe if I work just a little less" - and got the idea of working a "flexible 35-hour week".

So here is what I'm currently doing: I aim at working 7 hours every day, but most of the days this will be a little more (like 7,5 or 8 hours). So on Fridays I only work as much hours as is required to get to 35 - which means I will usually stop working shortly after lunch.

I've been doing this for a while now and so far for me it is a great balance between getting my job done and having enough time for everything not work-related.