I asked my then employer if I could drop to 4 days a week, pro-rata, and was surprised when the answer was yes! I had a few months last year on 5 days again, and it was still too much.
We're lucky enough to be able to afford the reduction in salary & benefits, and I won't go back to 5 days if I can avoid it.
For me the benefits are:
* more time with family.
* better time with family, because I have more energy.
* more time for chores, paperwork etc
* more time,energy & motivation for my own interests
* more time to cook good food & make/mend things reduces costs mitigating the salary reduction.
More interesting is that - counterintuitively - I still get about the same amount of work done as on 5 days, and I think it's better quality too.
I have nothing but good things to say about 4-day weeks and would love to see more of it in tech industry (and others too).
Even though I have the flexibility to just not work for an hour while I call about why my daughter hasn't been added to our insurance policy, I'm wondering what people without that flexibility do? If I ever have the opportunity to have employees I hope these experiences will help me be a better and more understanding employer.
When I reduced my hours, I was amused to notice that everyone from the VP who approved it down to the person in HR who handled the paperwork said they wished they could do the same. I told them all that they could. Most of us in this industry can get by on less, and be happier for it. If you're willing to push for it, any even marginally sane employer will do the calculations for letting you do it vs. hiring a replacement, and make the right decision. Sometimes the paperwork gets a bit messy, but if you show a willingness to work with people on that it can get done - and every person like me who has already gone down this road probably makes it a bit easier for others. In another decade this will be practically normal, just like working from home used to be weird but is now commonplace.