How exactly does the calworkhours() function work?

I'm aware that given a starting and ending date/time and a calendar, it will calculate the business hours between those two days, not including weekends/off hours if indicated in your calendar. In our calendar, our business days are 12:03 AM to 11:59 PM (as per business requirement), which means there is 23.95 working hours per day. Are these working hours rounded when calworkhours() generates a value? Are they rounded up? Rounded down? Is each working day rounded first or rounding happens after all the working hours are added. Any help is greatly appreciated!