sum of time: pivot table

[deafpride]

I am trying to find out the exact sum of time down to the hh:mm:ss on my pivot table from different people on different dates (in half hour increments).

Hence:

Columns: name name name name name
Rows:
01-01-2010 12:00
01-01-2010 12:30



I need a sum of time from each column WITHOUT the dates included in my sum.

This is a tricky one for me. HELP!