Calculate week no based on financial year

Question

Hi
Financial year starts with 01-Apr . I need to calculate week no based on 01-APR(financial year) not 01-Jan
for each date. Is there a way to calculate based on this

Answer 1

It works for all year long :-)
SQL> ed
Wrote file afiedt.buf
  1  with testdata as (
  2     select date '2011-04-01' + 7 * (level-1) dt from dual
  3     connect by level <= 60
  4  )
  5  --
  6  -- End of test data
  7  --
  8  select
  9  to_char(dt,'YYYY-MM-DD') the_date,
10  to_char(add_months(dt,-3),'WW') fiscal_week,
11  to_char(add_months(dt,-3),'IW') iso_fiscal_week
12  from testdata
13* order by dt
SQL> /
THE_DATE   FI IS
2011-04-01 01 52
2011-04-08 02 01
2011-04-15 03 02
2011-04-22 04 03
2011-04-29 05 04
2011-05-06 06 05
2011-05-13 07 06
2011-05-20 08 07
2011-05-27 09 08
2011-06-03 09 09
2011-06-10 10 10
2011-06-17 11 11
2011-06-24 12 12
2011-07-01 13 13
2011-07-08 14 14
2011-07-15 15 15
2011-07-22 16 16
2011-07-29 17 17
2011-08-05 18 18
2011-08-12 19 19
2011-08-19 20 20
2011-08-26 21 21
2011-09-02 22 22
2011-09-09 23 23
2011-09-16 24 24
2011-09-23 25 25
2011-09-30 26 26
2011-10-07 27 27
2011-10-14 28 28
2011-10-21 29 29
2011-10-28 30 30
2011-11-04 31 31
2011-11-11 32 32
2011-11-18 33 33
2011-11-25 34 34
2011-12-02 35 35
2011-12-09 36 36
2011-12-16 37 37
2011-12-23 38 38
2011-12-30 39 39
2012-01-06 40 40
2012-01-13 41 41
2012-01-20 42 42
2012-01-27 43 43
2012-02-03 44 44
2012-02-10 45 45
2012-02-17 46 46
2012-02-24 47 47
2012-03-02 48 48
2012-03-09 49 49
2012-03-16 50 50
2012-03-23 51 51
2012-03-30 52 52
2012-04-06 01 01
2012-04-13 02 02
2012-04-20 03 03
2012-04-27 04 04
2012-05-04 05 05
2012-05-11 06 06
2012-05-18 07 07
60 rows selected.ISO Week (IW) works with a different way of defining week 01. Using IW April 1st will become week 52. You will have to decide if that is correct according to your finance department :-)