Is there away to go through excel and sum the only the total hours
that someone has worked for each day

The format that my excel worksheet is:

Name1
12/15/2007 0:41 | Out
12/15/2007 0:44 | Out
12/15/2007 0:44 | IN
12/15/2007 0:44 | IN
12/15/2007 16:11 | IN
12/15/2007 16:18| Out
12/17/2007 9:03 | IN
12/17/2007 12:27 | OUT
12/17/2007 12:51 | IN
12/17/2007 17:08| Out

Etc for all users the "|" represents the next column

In the last column I have calculated all if the times by using the
following formula in a Macro

=A4-A3+IF(A3A4,1)

But this gives me everything. Now I need to calculate just the times
that the person has worked throughout one day (it does not matter if
it is during a weekend; I just need the total hours)