This is awesome. How did you manage to convince your employers, of 4 day work week? I was just thinking about it, I don't think there is any chance that I can convince my own employer of it :(
I did give up 20% of my salary and occasionally when there was an emergency and everyone showed up Saturday morning to make a delivery, I would also show up and not bill for those hours. This only happened a few times a year.
If you don’t ask for stuff, you are unlikely to get it.