I should actually be working 8h a day, but most of it is spend not working. If I'm honest I'm probably working more like 3h a day even though I enjoy my job.
I believe working 2-3 days a week would actually be enough and with the right organization method would allow even crucial 24/7 positions to be manned (like nursing and care staff). Plus you'd basically never be understaffed because you'd have lots of backups.