I don’t know the answer to that, but it’s basic rule of thumb. I’m available for a certain amount of days which I’m paid a certain amount of hours for. They get the choice whether to use me or the other guy. If I choose to work OVERTIME, I should be paid for that accordingly. In fact all over time should be time and a half like literally every other industry in the nation. Hell let me pick up extra reserve days without letting the line holders do it. Just make it fair.