I'm using these functions that return the non-weekend seconds between two dates:
CREATE FUNCTION [dbo].[DateDiff_NoWeekends](
@date1 DATETIME,
@date2 DATETIME
)
RETURNS INT AS BEGIN
DECLARE @retValue INT
SET @date1 = dbo.__CorrectDate(@date1, 1)
SET @date2 = dbo.__CorrectDate(@date2, 0)
IF (@date1 >= @date2)
SET @retValue = 0
ELSE BEGIN
DECLARE @days INT, @weekday INT
SET @days = DATEDIFF(d, @date1, @date2)
SET @weekday = DATEPART(dw, @date1) - 1
SET @retValue = DATEDIFF(s, @date1, @date2) - 2 * 24 * 3600 * ((@days + @weekday) / 7)
END
RETURN @retValue
END
GO
CREATE FUNCTION [dbo].[__CorrectDate](
@date DATETIME,
@forward INT
)
RETURNS DATETIME AS BEGIN
IF (DATEPART(dw, @date) > 5) BEGIN
IF (@forward = 1) BEGIN
SET @date = @date + (8 - DATEPART(dw, @date))
SET @date = DateAdd(Hour, (8 - DatePart(Hour, @date)), @date)
END ELSE BEGIN
SET @date = @date - (DATEPART(dw, @date)- 5)
SET @date = DateAdd(Hour, (18 - DatePart(Hour, @date)), @date)
END
SET @date = DateAdd(Minute, -DatePart(Minute, @date), @date)
SET @date = DateAdd(Second, -DatePart(Second, @date), @date)
END
RETURN @date
END
This should help to get started to find also the solution for the other tasks.
Here's a sql-fiddle demo with your sample data:
SELECT [weekday-seconds between] =
(dbo.DateDiff_NoWeekends('2014-10-01 10:33:57.767','2014-10-09 10:33:52.733'))
=> 518395