I'm a bit more concerned about user input errors. I think you need a check
that the starting and ending dates are in fact workdays, i.e,

=IF(NETWORKDAYS(A1,A1)=1,18/24-MOD(A1,1),0)
+IF(NETWORKDAYS(B1,B1)=1,MOD(B1,1)-8/24,0)
+NETWORKDAYS(A1+1,B1-1)*9/24


On Tue, 22 Mar 2005 23:29:08 -0800, "Biff" wrote:

Hmmm...

That can be slightly shortened to:

=SUM(18/24-(A1-INT(A1)),(B1-INT(B1))-8/24)+(NETWORKDAYS
(A1,B1)-2)*9/24

Biff

-----Original Message-----
Hi!

Do you want to exclude any holidays that fall on regular
business days?

A1 = 17/12/2004 10:07
B1 = 3/02/2005 15:22

=SUM(17.5/24-MOD(A1,INT(A1)),MOD(B1,INT(B1))-8.5/24)+
(NETWORKDAYS(A1,B1)-2)*9/24

Format the cell as [h]:mm.

If you want to exclude holidays you need to make a list
of
holidays and then include a reference to that list as a
3rd argument in the NETWORKDAYS function.

Example:

Say you list holidays in the range C1:C10.

Include that range in the NETWORKDAYS function:

.....NETWORKDAYS(A1,B1,C1:C10)....

Biff

-----Original Message-----
Hi
I am trying to calculate the elspased time between
certain dates and times
with a result in total hours.

The catch is that I only want the formula to inlcude
times during business
hours (Monday to Friday, 8:30am - 5:30pm)

E.g (17/12/2004 10:07) - (3/02/2005 15:22) = ???

Is this possible with excel?

Many thanks

.

.