Calculating time differences across two (or more) dates

Hello all,

What I'm trying to do is to calculate the time difference between two date/times.

eg I have

01/05/2006 18:00 in A1 and 02/05/2006 05:30 in B2

How can I calculate the number of hours and minutes that have elapsed between A1 and B2?

Currentley I have the cells in dd/mm/yyy hh:mm:ss format but can change this if needs must.....

Thanks for yer time!

b2-a1

Format number as a custom format

[hh]:mm

Regards

Dav