Reduced Work Week and Compressed Work Week are a (relatively) new concept that some Annualised Hours Contract workplaces are doing
Reduced: You work 4 days of 7.5 hours, adding up to 30 hours weekly, you get paid the same as if you worked 5 days of 7.5 hours (37.5 hours)
Compressed: You work 4 days of 9.5 hours, adding up to 37.5 hours weekly, you get paid the same as if you worked 5 days of 7.5 hours (37.5 hours)
It’s not illegal in the US unfortunately. We clock out and can leave if we want but we have to clock back in after 45 mins. I think the only legal requirement is that there is time allowed for a break after x number of hours worked but it doesn’t have to be paid.