for example : a day thats a short day, lets say erev yom tov , Tzom Gedlya , Etc.
if we mark a student Absent for the day it shouldn't mark him as he missed all classes for the day after 12:00
so if we can enter (Black out ) that a particular day the day ends at 12:00 so if we enter absent all day he doesn't get an absent for all programs of a regaler day.
like this we have accurate reporting we know he missed 6 times this class not 7 or 8 times .