calculations in group footer

Could someone direct me to an example on how to calculate a sum by group? I'm retrieving the data from SQL.  Example format below.  Thanks
(i was able to sum the total on the footer but need to group by date and calculate the sum.)

Name     date                  hours
Ale        12-3-2011            3.0
Joe        12-3-2011            4.0
Total                                  7.0
Jack        12-4-2011            2.3
Jack        12-4-2011            1.2
Jack        12-4-2011            1.5
Total                                    5.0