Primavera calendar problem

Exhibit 1 shows that 4 of the project activities have a duration of 12 days. Exhibit 2 shows that there are 8 hours in a work day. Exhibit 3 is the exported .xer file. Exhibit 4 shows that when the .xer file is exported the number of hours for the 12 day duration is 95 and not 96 whereas all the other durations are a multiple of 8. Exhibit 5 confirms that clndr_id 178 is the “Corporate – Standard Full Time” calendar. If you know the reason and solution for the above problem please would you let me to how much you would charge for enlightening me.