A few months ago, I requested a 32 hour work week at my job. I took the appropriate paycut (I'm a single bachelor that doesn't spend much anyway). Instead of a 4-day workweek, I do ~6.5 hours for 5 days. It's been great and I couldn't recommend it more.

edit - I should add that I started the job at 40 hours/week, and after 1 year of being there I asked for 32 hours/week.