I am using the following script to determine what the business days are for each particular month.
DECLARE @startdate DATETIME
SET @startdate ='20170401'
;
WITH bd AS(
SELECT
DATEADD(DAY,
CASE
(DATEPART(WEEKDAY, DATEADD(MONTH, DATEDIFF(MONTH, 0, @startdate), 0)) + @@DATEFIRST - 1) % 7
WHEN 6 THEN 2
WHEN 7 THEN 1
ELSE 0
END,
DATEADD(MONTH, DATEDIFF(MONTH, 0, @startdate), 0)
) AS bd, 1 AS n
UNION ALL
SELECT DATEADD(DAY,
CASE
(DATEPART(WEEKDAY, bd.bd) + @@DATEFIRST - 1) % 7
WHEN 5 THEN 3
WHEN 6 THEN 2
ELSE 1
END,
bd.bd
) AS db,
bd.n+1
FROM bd WHERE MONTH(bd.bd) = MONTH(@startdate)
)
SELECT * INTO #BD
FROM (
SELECT 'BD'+ CAST(n AS VARCHAR(5)) AS Expected_Date_Rule, bd AS Expected_Calendar_Date
from bd
) AS x
The result of this table works fine. Bd is the the calendar days for the particular month and n is the business day number. The script does its job of not counting the weekend as a business day.
bd n
----------------------- -----------
2017-04-03 00:00:00.000 1
2017-04-04 00:00:00.000 2
2017-04-05 00:00:00.000 3
2017-04-06 00:00:00.000 4
2017-04-07 00:00:00.000 5
2017-04-10 00:00:00.000 6
2017-04-11 00:00:00.000 7
2017-04-12 00:00:00.000 8
2017-04-13 00:00:00.000 9
2017-04-14 00:00:00.000 10
2017-04-17 00:00:00.000 11
2017-04-18 00:00:00.000 12
2017-04-19 00:00:00.000 13
2017-04-20 00:00:00.000 14
2017-04-21 00:00:00.000 15
2017-04-24 00:00:00.000 16
2017-04-25 00:00:00.000 17
2017-04-26 00:00:00.000 18
2017-04-27 00:00:00.000 19
2017-04-28 00:00:00.000 20
2017-05-01 00:00:00.000 21
But then I notice that a potential issue will occur in July where the output will count the 4th of July as BD2 when it should be counted as BD3. Some had created a holiday table that is updated with all the holidays (excuse the bad spelling).
Holiday table
1 2017-01-01 New Year Day
4 2017-01-02 New Year Day-Follow
1 2017-01-16 MArtin Luther King Day
4 2017-01-17 MArtin Luther King Day-Follow
1 2017-02-20 Preseiednt Day
4 2017-02-21 Preseiednt Day-Follow
1 2017-05-29 Memorial Day
4 2017-05-30 Memorial Day-Follow
1 2017-07-04 Independence Day
4 2017-07-05 Independence Day-Follow
1 2017-09-04 Labour Day
4 2017-09-05 Labour Day-Follow
1 2017-10-09 Columbus Day
4 2017-10-10 Columbus Day-Follow
1 2017-11-10 Vetrans Day
4 2017-11-11 Vetrans Day-Follow
1 2017-11-23 ThanksGiving
1 2017-11-24 Day After Thanks Giving
4 2017-11-24 ThanksGiving-Follow
4 2017-11-25 Day After Thanks Giving-Follow
1 2017-12-25 Christmas
4 2017-12-26 Christmas-Follow
I was thinking there may be some way I can update my script to check the holiday table and skip the holiday and dont count it as a business day. Any tips?
