I have a worksheet that calculates process times. I have a formula that
calculates process times and excludes weekends and non working hours. How do
I get it to skip holidays?

This is my formula I'm using now:

=IF(A19="NA",(0),(NETWORKDAYS(B19,M19)-1)/2.4+(N19-C19))

b19 is date in, m19 is date out, n19 is time out, and c19 is time in.

Do I have to specify somewhere what the holidays are? I'm using 2007 if
that makes any difference.

Tania