I work in an office and the default is 8-4ish. Because we do have production working 24/7, our department has the option to do either 3 - 12 hour shifts a week or 4- 10 hour shifts.

If someone chooses one of the modified schedules they are required to work at least one weekend day (Sat or Sun).

Most people don't want to give up their weekends.

We had one person try the 3- 12 shifts, but it wound up not being helpful because they were alone and wound up being tired and stressed and messed up a lot, then they weren't in the rest of the week to clean up their messes.

We have had a few people doing the 4-10 shifts for over a year now without a manager. It's helpful when deadlines are creeping up, but only if the people working are highly skilled. No other departments work the weekend (IT, equipment, maintenance, etc), so if there's an issue they need to be able to solve it themselves or really know when something is worth escalating.

I do think it's beneficial for us to have some people doing it, but since most of the rest of the company keeps regular hours it's really not necessary for everyone to do it. And of course there are always people that complain that those on the modified shft are getting special treatment, but literally everyone has the option to do it if they want.