I am trying to set up a start time and end time worksheet to calculate total hours between evolutions. When I put my start date in A2 and my end time in B2 the difference I get is 7 hours. The time I am using is start 0900am (8/2/02) and end 1600 (8/3/02). This should be a difference of 31 hours in reality. Cannot get it to work in excel. Please help