I don’t get paid the overtime rate until I’ve recorded 40 hours of work. On a PTO or holiday week, that becomes a 50% loss on value for each OT hour worked below 40 hours. In some places (California) that could be a 100% loss or more on the overtime rate. If you shift the labor into prior or subsequent weeks you get a big boost in pay for the same hours. By not knowing the rules of the game you’re losing money.