Week calculation from a specific period

Question

suppose the fiscal year is starting from July/1st to June/30th.

I have to calculate the week no. accordingly in SQL Server 2005.

Please Suggest!

Many Tha

Answer 1

Try this and use variable @dt for your own needs:

DECLARE @dt DATETIME = GETDATE()
SELECT WeekOfMonth = DATEPART(wk, @dt) - DATEPART(wk,DATEADD(m, DATEDIFF(M, 0, @dt), 0)) + 1

EDITED: My fault as I incorrectly understood the question, my solution returns the week of the month, not of the year.

Using part of @Dems answer and changing mine here is a full working test that outputs 3 columns WeekOfMonth, WeekOfYear and WeekOfFIscalYear based on date and begining of fiscal year available on a temporary table. But I guess the begining of a fiscal year will be always the same for a particular company. I just added different dates and years for testing.

DECLARE @TT TABLE (auxVal       INT,
                   auxdate      DATETIME,
                   fiscal_year  DATETIME
                )

INSERT @TT 
SELECT 100,'19120101 00:00:00','19120701' UNION ALL
SELECT 200,'18120615 00:00:00','18110701' UNION ALL
SELECT 100,'20121121 00:00:00','20120701' UNION ALL
SELECT 200,'20120101 00:00:00','20110701' UNION ALL
SELECT 100,'20150802 00:00:00','20140701' UNION ALL
SELECT 200,'20120330 00:00:00','20110701' UNION ALL
SELECT 322,'20110228 00:00:00','20100701'

SELECT DATEDIFF(week, DATEADD(MONTH, DATEDIFF(MONTH, 0, auxDate), 0), auxDate) + 1 WeekOfMonth,
       DATEPART( wk, auxDate) WeekOfYear,
       DATEDIFF(DAY, (DATEADD(YEAR, DATEDIFF(YEAR, fiscal_year, DATEADD(MONTH, -7, auxDate)), fiscal_year)), auxDate) / 7 + 1  WeekOfFiscalYear
  FROM @TT

Result:

WeekOfMonth   WeekOfYear   WeekOfFiscalYear
-------------------------------------------
      1            1             27
      3            25            51
      4            47            21
      1            1             27
      2            32            5
      5            13            40
      5            10            35
-------------------------------------------