Displaying Difference between Two dates in Hours in Reports
From SmartWiki
To calculate difference between two dates in hours in the Reports, we can use the following syntax:
24*(To_days(enddate)-To_days(startdate))+(hour(enddate)-hour(startdate))+((minute(enddate)-minute(startdate))/60)
where the enddate and startdate may be replaced by column numbers. For example, if the Startdate is displayed in column 1 and Enddate is displayed in column 2 then the syntax would be:
24*(To_days([2])-To_days([1]))+(hour([2])-hour([1]))+((minute([2])-minute([1]))/60)