Qui trovi un esempio

http://www.mssqlcity.com/FAQ/Devel/get_working_days.htm

Mentre quella che segue è una soluzione proposta in un ng da Steve Kass, MVP di SQL Server, che tiene conto anche di eventuali festività infrasettimanali

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create table Calendar (
d smalldatetime primary key,
c varchar(10) not null
check (c in ('WORKDAY','WEEKEND','HOLIDAY'))
)
go


declare @d smalldatetime
set @d = '20030101'
while @d < '20050101' begin
insert into Calendar values (@d, 'WORKDAY')
set @d = @d + 1
end


update Calendar
set c = 'WEEKEND'
where datepart(weekday,d) = 1
or datepart(weekday,d) = 7


update Calendar
set c = 'HOLIDAY'
where d in
('20030101','20030418','20030526','20030703',
'20030704','20030901','20031127','20031128',
'20031225','20031226')
go


declare @d datetime
set @d = '20030701'
declare @wdaysahead int
set @wdaysahead = 15


select min(d) as Later
from Calendar C1
where d >= @d + 15
and (
select count(*)
from Calendar C2
where C2.d > @d
and C2.d <= C1.d
and C2.c = 'WORKDAY'
) = @wdaysahead
go
=========================

Evita di scrivere in maiuscolo...

Bye