One of my last employers did this and I begged them to just let a couple people work a five day schedule that included Saturday and or Sunday (I wanted to be one of those people) so we could deploy any day, trouble shoot any day, but they were against it. I think people need two (actually at least three, but that's a different discussion) days off every week, but I also don’t think people need to work identical schedules. Put another way: you must give the castle guards a break from staving off attacks but you must not give them all the same break.