Time is measured as a fraction of a day. If you keep the
hh:mm or hh:mm:ss formatting you can calculated with time, but
Excel will not format negative times. If you have a total where
hours may reach or exceed 24 hours you want to format as
[hh]:mm to keep the hours from rolling off into days.

If you want to use time in a calculation that uses hours then you must
multiply the time by 24 for hours worked.

For more information on Dates and Times, and how to measure
time worked through midnight see these pages.
http://www.mvps.org/dmcritchie/excel/datetime.htm
http://www.cpearson.com/excel/datetime.htm


i;e.
B2: 22:50
C2: 03:50
D2: =C2-B2+(B2<C2)

---
HTH,
David McRitchie, Microsoft MVP - Excel [site changed Nov. 2001]
My Excel Pages: http://www.mvps.org/dmcritchie/excel/excel.htm
Search Page: http://www.mvps.org/dmcritchie/excel/search.htm

"Search33" wrote in message ...
You should be able to just use a simple subtraction
for example, A1=9 am A2=12 pm A3=A2-A1 gives the result in A3 as 3:00 AM
you can then format A3 as custom and put h. This should give you 3

"Dragonrana" wrote:

I have a start date and an end date.What I need is to give the difference in
hours? How do I do that?

i.e. 9:00AM (Start Date)
12:00 PM (End Date)

Result : 3 hours

Thanks.