Determining if a Date is a Weekday in T-SQL

create function fn_IsWeekDay ( @date datetime ) returns bit as begin declare @dtfirst int declare @dtweek int declare @iswkday bit set @dtfirst = @@datefirst – 1 set @dtweek = datepart(weekday, @date) – 1 if (@dtfirst + @dtweek) % 7 not in (5, 6) set @iswkday = 1 –business day else set @iswkday = [...]