Determine 4 working days from Start Of Month

  • Hello,

    I have a scenario where I want to add 4 working days to the start of a month.

    Background:

    My users currently have a transaction table where they filter on a YearMonth to view transactions for a Month for example '201001' will return all transactions for January 2010.

    There is now a new requirement that transactions that fall in the first 4 working days of the Month should pertain to the previous month (Call it 'YearMonthMIS').

    In the sql below I've described what I expect my result to look like however it only adds 4 days not work days.

    *Note the second SELECT indicates the basis of my calcs.

    --Temp table:

    CREATE TABLE #tempTransactions

    (ID int PRIMARY KEY

    , TransactionDate DATETIME

    , TransactionYearMonth int

    )

    INSERT INTO #tempTransactions

    SELECT 1, '01/01/2010', 201001

    UNION ALL

    SELECT 2, '01/05/2010', 201001

    UNION ALL

    SELECT 3, '01/30/2010', 201001

    UNION ALL

    SELECT 4, '02/02/2010', 201002

    UNION ALL

    SELECT 5, '02/15/2010', 201002

    --Retrieve results:

    SELECT

    ID

    , TransactionDate

    , TransactionYearMonth

    -- IF Transaction date is Between the [FirstDayOfMonth] AND [FirstDayOfMonthMIS] THEN YearMonthMIS is = Previous YM

    , CASE WHEN TransactionDate BETWEEN (DATEADD(month, DATEDIFF(month, 0, TransactionDate), 0)) AND (DATEADD(DAY, 4, (DATEADD(month, DATEDIFF(month, 0, TransactionDate), 0))))

    THEN YEAR (DATEADD(MONTH, -1, TransactionDate)) *100 + MONTH(DATEADD(MONTH, -1, TransactionDate))

    ELSE TransactionYearMonth

    END AS [YearMonthMIS]

    FROM

    #tempTransactions

    --Basis of Calculations:

    SELECT

    TransactionDate

    , TransactionYearMonth

    --(TransactionYearMonth -1):

    , YEAR (DATEADD(MONTH, -1, TransactionDate)) *100 + MONTH(DATEADD(MONTH, -1, TransactionDate)) AS [PreviousTransactionYearMonth]

    --FirstDay of Month:

    , DATEADD(month, DATEDIFF(month, 0, TransactionDate), 0) AS [FirstDayOfMonth]

    --FirstDay of Month +4 days):

    , DATEADD(DAY, 4, (DATEADD(month, DATEDIFF(month, 0, TransactionDate), 0))) AS [FirstDayOfMonthMIS]

    FROM #tempTransactions

    DROP TABLE #tempTransactions

    The crux is thus to replace the 4 below with 4 working days:unsure:.

    DATEADD(DAY, 4, (DATEADD(month, DATEDIFF(month, 0, TransactionDate), 0))) AS [FirstDayOfMonthMIS]

    If anyone has any suggestions or advice it would be greatly appreciated!

    G

  • In order to have working days you will need to create a calendar like in this article

    Fun with business days, calendar tables, and test-driven development - By Alex Kuznetsov, 2010/09/23 [/url]

    Or are you considering working days: Monday to Friday?

    Regards,

    Iulian

  • What is your definition of a working day? Does this exclude public holidays as well as weekends?

    If so, a date table will be the simplest solution, keyed on date, specifying the month that it relates to.

  • Hi,

    To calrify Work Day is Monday to Friday. Holidays are not material for the purpose of this report.

    I would like to avoid the use of calender table if at all possible but at the moment I can't see a solution.

    Thanks for taking time to reply.

    G

  • Here you will need to determine and add the numbers of weekend days.

    and the code will be

    4 + [weekend days in the first 4 days of the month]

    Regards,

    Iulian

  • The number of the weekend days in the first 4 days of the month can be determined using datepart function, something like this: CASE WHEN DATEPART( WEEKDAY, GETDATE()) BETWEEN 2 AND 4 THEN 0

    ELSE 2

    END

    It depends when your week starts.

    Regards,

    Iulian

  • If the first day of the month is 'saturday', add 5 days. If it's a 'sunday', add 4 days. What if it's wednesday?

    -- How might this work longhand?

    DECLARE @MyDate DATETIME

    SET @MyDate = GETDATE()

    SELECT

    [Weekday] = DATENAME(weekday,@MyDate+0),

    [4 wd later] = DATENAME(weekday,DATEADD(dd,4,@MyDate+0)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+1), DATENAME(weekday,DATEADD(dd,6,@MyDate+1)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+2), DATENAME(weekday,DATEADD(dd,6,@MyDate+2)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+3), DATENAME(weekday,DATEADD(dd,6,@MyDate+3)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+4), DATENAME(weekday,DATEADD(dd,6,@MyDate+4)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+5), DATENAME(weekday,DATEADD(dd,5,@MyDate+5)) UNION ALL

    SELECT DATENAME(weekday,@MyDate+6), DATENAME(weekday,DATEADD(dd,4,@MyDate+6))

    -----------------------------------------------------------------------------

    -- tidy it up a little

    DECLARE @Increment TINYINT

    SELECT @Increment = CASE

    WHEN DATENAME(weekday,@MyDate) = 'Monday' THEN 4

    WHEN DATENAME(weekday,@MyDate) = 'Tuesday' THEN 6

    WHEN DATENAME(weekday,@MyDate) = 'Wednesday' THEN 6

    WHEN DATENAME(weekday,@MyDate) = 'Thursday' THEN 6

    WHEN DATENAME(weekday,@MyDate) = 'Friday' THEN 6

    WHEN DATENAME(weekday,@MyDate) = 'Saturday' THEN 5

    WHEN DATENAME(weekday,@MyDate) = 'Sunday' THEN 4

    END

    SELECT DATEADD(dd, @Increment, @MyDate)

    -----------------------------------------------------------------------------

    -- final version

    SET @MyDate = GETDATE()

    SELECT Today = @MyDate, ReportStartDate = DATEADD(dd, CASE

    WHEN DATENAME(weekday,@MyDate) = 'Saturday' THEN 5

    WHEN DATENAME(weekday,@MyDate) IN ('Monday','Sunday') THEN 4

    ELSE 6 END, @MyDate)

    “Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw

    For fast, accurate and documented assistance in answering your questions, please read this article.
    Understanding and using APPLY, (I) and (II) Paul White
    Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

  • Replace "4" with:

    4 + SUBSTRING('0012221', DATEDIFF(DAY, '19000101',

    DATEADD(month, DATEDIFF(month, 0, '20100301'), 0)) % 7 + 1, 1)

    SQL's base date, 19000101, is a Monday. So the string is the # of days to add for MonTueWedThu.... Then a quick computation determines the number of days to add.

    Scott Pletcher, SQL Server MVP 2008-2010

  • Thank you everyone for taking time to post, you have been most helpful!

    I went with Chris's solution as I found it easier to read (at least for me anyway :P)

    I made some adjustments to the actual days; I realised that I should only add 3 working days as the current transaction day is included.

    So it came down to: Sunday3+1; Mon and Tue 3+0; Everything else 3+2

    DECLARE @MyDate DateTime

    SET @MyDate = GetDate()

    SELECT DATEADD(dd, CASEWHEN DATENAME(weekday,@MyDate) = 'Sunday' THEN 4

    WHEN DATENAME(weekday,@MyDate) IN ('Monday', 'Tuesday') THEN 3

    ELSE 5

    END,@MyDate )

    Thanks again,

    G

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