In our local RO is put in the same way you put in for a 8 hour or vacation day with a slip turned into a supervisor. Here is the thing about RO's though, they are only guaranteed the day of so if you need the day off call in or PH or vacation day whatever you got left in time off. Basically you are rolling the dice hoping they don't call you the morning of saying so and so called in or we need a favor from you BS.