I don't have the experience to get you all the way, but I recently solved a
similar problem (calculating differences between dates only ... without
times) by referencing some Julian date calculators/conversions he
http://www.cpearson.com/excel/jdates.htm

That might be enough to get you started.

"vito" wrote:

I have two colums of data.

Date Charge Time
7/9/06 7:55
7/9/06 19:00
7/11/06 13:00
7/12/06 3:40
7/13/06 2:00
7/13/06 23:50

I would like to find the difference in charge time in a new column. How
would I go about doing this?