I need a formula that will calculate the amount of time (in hours) that it
takes us to respond to a request, but i need hours of operations and not
include weekends. Our hours of operations are 8am to 5pm. I have a submit
date and time, and a respond date and time fields. Here are two examples:

Submit field 11/26/08 4:00 pm
Respond field 11/27/08 9:00 am
Response time should be = 2 hours.

Submit field: 11/26/08 6:00 pm
Response field: 11/27/08 9:00 am
Response time should be = 1 hour