Using Time in access queries/reports

I am trying to subtract times on particular days and then total all used times in a report. I can not seem to get the proper format/input mask so that the times will subtract and then total across days. Example…equipment used from 9:00 am to 11:30 am (NEED 11:30-9:00 = 2:30) and then add all these times calculations for the month.

Thanks