4 day for 10. It help to save time on communte (when there is no global pendemic around)

IMO, 3 solid days to work on your project is better than trying to barter sleep on the 5 working days.

Working 4 days of 10 hours each is a good solution when you do not have to care that other are working 5 days of 8 hours. It may be not well and healthy for your family, example given: you always need to pick kids from kinder garden it's before closing hours

Currently on 5 days but I would love 4 so I have a solid 3 days to work on my side projects. It's about creating longer blocks.

5 days for 8 hrs..every day is important, don't want to exhaust 4 days to get one day.

I'd go for a 4 days week and 10 hours. Most of the time I work extra like 12, or 14 hours only because a lot of times when you started something you don't want to pause until it's sorted. 😄 Maybe plus the fact that you will always have things to do when running a start up.