Time calculation errors

I am having a problem with time calculations in AdobeSign.  I am using the dateDiff function to calculate hours on a timecard, and when the times are initially entered on the time sheet, the numbers are off (ex. 9am to 11 am and 2pm to 4pm calculates at 1,466 hours and 9am to 1pm calculates to 175,165 hours).  However, once the time sheet is signed and submitted, the pdf file contains the correct totals.  Is there any way to have the correct totals show when the numbers are initially entered?