I haven't used Crystal Reports enough to know what functions it has for date and time. But I think all you need to know are the functions "Now()" and "DateDiff()".
If you can't put those directly into Crystal Reports, build a query in Access that uses them.
ElapsedHours: DateDiff("h",yourdatetimefield,Now())
ElapsedHours will contain a positive number that is the number of hours between the data in your date field and the computer's time. Of course if you reverse the fields, you'll get a negative number.
Randall J Weers
Membership Vice President
Pacific NorthWest Access Developers Group
http://www.pnwadg.org