If someone gave me the chance of a 30-hour work week, I would rather work 4 days of 7,5 hours than 5 days of 6 hours. Just the hassle of getting up early, dressing up for work, commuting etc. isn't really worth it when I'm only going to work 6 hours anyway. I'd rather take an extra day off.
This is a fairly common thing here in the Netherlands actually, four day work week. Most of my colleagues I know who does this to have some extra time with their family/kids. Usually it's a split in the middle of the week or something, for example my manager doesn't work tuesday's, it's his "papadag" as he then spends time with his kids and don't have to send them off to day-care or get a nanny. Another colleague of…
For single parents going from 40 to 32 hours per week can be a net-neutral operation from a money perspective. The various tax breaks will increase with just about the same as your net salary drops. In rare cases you'll even end up with net a bit more than before. Going from 32 to 24 might still be the same, below that the balance shifts and you end up with less.
I just ran the numbers with one of my employees in NL and we came to this exact conclusion so she decided to work one day less. In countries with a strong social net the equation is not always as simple as time*hourly rate, your situation should be taken into account as well.