Count work days between two dates

Question

How can I calculate the number of work days between two dates in SQL Server?

Monday to Friday and it must be T-SQL.

Answer 1

That's working for me, in my country on Saturday and Sunday are non-working days.

For me is important the time of @StartDate and @EndDate.

CREATE FUNCTION [dbo].[fnGetCountWorkingBusinessDays]
(
    @StartDate as DATETIME,
    @EndDate as DATETIME
)
RETURNS INT
AS
BEGIN
    DECLARE @res int

SET @StartDate = CASE 
    WHEN DATENAME(dw, @StartDate) = 'Saturday' THEN DATEADD(dd, 2, DATEDIFF(dd, 0, @StartDate))
    WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN DATEADD(dd, 1, DATEDIFF(dd, 0, @StartDate))
    ELSE @StartDate END

SET @EndDate = CASE 
    WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN DATEADD(dd, 0, DATEDIFF(dd, 0, @EndDate))
    WHEN DATENAME(dw, @EndDate) = 'Sunday' THEN DATEADD(dd, -1, DATEDIFF(dd, 0, @EndDate))
    ELSE @EndDate END


SET @res =
    (DATEDIFF(hour, @StartDate, @EndDate) / 24)
  - (DATEDIFF(wk, @StartDate, @EndDate) * 2)

SET @res = CASE WHEN @res < 0 THEN 0 ELSE @res END

    RETURN @res
END

GO