Ask HN: I'm considering trying a 4-day work week. How has it worked out for you?

I'm considering experimenting with a 4-day work week for a few months. Does anyone have feedback on how this has worked or not worked for them?

A little background with some of the reasons why:

-Not convinced I currently have 40 hours of work to do. Either I'm wasting time or not finding enough work to do.

-My wife and I have a 3-month old daughter and I want to spend more time with them

-Errands that need to be done during business hours (dr. appts, dmv, social security office, etc..)