Look at this thread: Variance calculation
Especially Dave’s sample code should be a good starting point:
=((( (ToNumber(SubStr(FormatDate(<DATE2> ,"HH:MM:SS") ,1 ,2))*60*60) +
(ToNumber(SubStr(FormatDate(<DATE2> ,"HH:MM:SS"), 4, 2))* 60) +
ToNumber(SubStr(FormatDate(<DATE2> ,"HH:MM:SS"), 7, 2))) - (
(ToNumber(SubStr(FormatDate(<DATE1> ,"HH:MM:SS") ,1 ,2))*60*60) +
(ToNumber(SubStr(FormatDate(<DATE1> ,"HH:MM:SS"), 4, 2))* 60) +
ToNumber(SubStr(FormatDate(<DATE1> ,"HH:MM:SS"), 7, 2)))) / 3600) +
(DaysBetween(<DATE1> ,<DATE2>)*24)
I believe there is also a DLL one of the BOB members wrote which allows adding time.
Andreas (BOB member since 2002-06-20)