It is not a trivial task by any means. See
http://www.cpearson.com/Excel/DateTimeWS.htm#WorkHours for a rather
involved formula that will return the number of working days and hours
between a start date and time and an end date and time, given a
working day start time and end time.

Cordially,
Chip Pearson
Microsoft MVP
Excel 1998 - 2010
Pearson Software Consulting, LLC
www.cpearson.com
[email on web site]

On Tue, 10 Nov 2009 07:27:39 -0800 (PST), LJ
wrote:

I am currently using the following formula to figure out how long a
request takes to be completed. This formula accounts for time spent
in a pending status, which is factored-out of the total.

=IF(ISBLANK(D2),B2-C2,D2-C2)

B2 = Date and Time issue was resolved
C2 = Date and Time issue was opened
D2 = Date and Time issue was placed in pending status

I need a formula that will factor-out the time after business hours; a
NETWORKDAYS formula or something similar that will work with the above
formula. Thanks in advance for the assistance.

LJ