The problem is, it isn't really ethical to do it that way. Think about it. Let's say you work 48 hours this week. And let's say you work 8 hours on Friday. This means that you get 8 hours of OT pay at time and a half (because it is legally required), but you have given up the time and a half holiday pay because that isn't legally required. And you shouldn't have to give up holiday pay simply because you are in OT...there is nothing in the handbook that says you can forfeit your holiday pay, which is basically what they force you to do.