When I was in high school, there were like six periods in a day and we had a five minute break between four of the periods and a 10-minute break between two of the periods. That was sufficient time to take care of bodily functions, barring illness.
"Smokin' in the Boys Room"...? Sounds about right. Great RnRoll band.
15 times a month should be enough for all but the worst of the 'Chronic Urinators.'