Workday syntax

Hi,
I have
=DATE(YEAR(C3),MONTH(C3),DAY(C3)+D3+E3+F3+5) where the +5 is weekends and holidays

I tried =workday(YEAR(C3),MONTH(C3),DAY(C3)+D3+E3+F3+0)
I just can't get the sytax correct for my start date and adding the days, and once I get that correct I would like to add holidays.
Thanks
alan