Apologies i misread your post you want the start date, Try this

=A1-(DAY(WORKDAY(A1,A2,B1:B8)))

End date in a1
days work in a2

Mike

"bau" wrote:

Hi all,
Say that I have a project which must be completed by Sept 05 2007 and it
will take 3 days to complete it. Since Sept 1 and 2 are weekend and Sept 03
is a holiday, also, Mr. A, who will perform this task will take a vacation on
Sept 04. What formular I have to use?
Sheet1:
Column A Column B Column C
Duration Start date End date

3 ??? 9/04/07

Sheet2 (vacation / holidays):
Column A Column B Column C Column D

Holidays Mr. A Mr. B Mr. C

9/03/07 9/04/07 9/07/07 8/31/07

Thanks,
Bau