At least in my experience, it really helps to have one senior person lead the way. Our company hired a greybeard with a rock solid condition of his employment

At least in my experience, it really helps to have one senior person lead the way. Our company hired a greybeard with a rock solid condition of his employment being a four day work week. After that, it was much easier for "normal" employees to switch to it since management was familiar with the idea and saw that he was a very productive employee. I switched to four day work weeks when I was 29 (based on his example) and have been very happy with it.