How coin-in/slot club hours work

So I'm a VP player mostly. Let's say I'm going to down to our friendly native America casino tonight (which, I am). I won't get there until about 9:30pm. If the casino calculates my per-day coin-in and uses that to determine my comp level, would I be better off waiting until AFTER MIDNIGHT tonight to play, therefore making my daily coin-in average look better?

Or am I off here?

Ask the booth when their days begin. I seem to remember the Harrahs properties in AC did a 4am to 4am day.