Sure, try the following...

Insert > Name > Define

Name: BigNum

Refers to: =9.99999999999999E+307

Click Ok

Then try...

=LOOKUP(BigNum,CHOOSE({1,2},0,AVERAGE(IF(Daily!$A$4:$A$604>Weekly!A4,IF(D
aily!$A$4:$A$604<=Weekly!A5,IF(Daily!$B$4:$B$604<>"",Daily!$B$4:$B$604)))
)))

....confirmed with CONTROL+SHIFT+ENTER. The formula will return 0
instead of #DIV/0!. If you'd like the cell to be blank, you can custom
format the cell...

Format > Cell > Number > Custom > Type: [=0]""

Hope this helps!

In article <gimiv.2a83rb_1151684407.5949@excelforum-nospam.com>,
gimiv <gimiv.2a83rb_1151684407.5949@excelforum-nospam.com> wrote:

> It worked. Thanks again. One more thing. Is there a way to set it so
> that if there are noe values to calculate, you don't get the #DIV/0!
> error?