If a cell has a similar value to the one above it, total adjacent columns

Hi One and All,

I would normally ask for help from a colleague but as its a saturday he isn't around and I would like to get this to work today if at all possible.

Here's what I am after trying to achieve:

If a cell has a date in it that is the same as a cell above, I would like to total time values in cells that are adjacent to these original cells. Maybe the example below explains it better.

A1 A2 A3
01/01/09 1:00
01/01/09 3:00 4:00
02/01/09 0:10 0:10
03/01/09 0:50
03/01/09 0:50 1:40