Why would you need to _calculate_ these values?
Because, expression must be get longer and complex.
If you know shorter expression than one in the following example,
please show me that.
------------------------------ Commands Entered
------------------------------
SELECT d
, DATE(
SUBSTR(CHAR(d + (SIGN(QUARTER(d)-1)-1) YEAR),1,5)
|| CASE QUARTER(d)
WHEN 1 THEN '12-31'
WHEN 2 THEN '03-31'
WHEN 3 THEN '06-30'
WHEN 4 THEN '09-30'
END
) AS "last day of previous quarter 1"
, d - DAYOFYEAR(d) DAYS + ((QUARTER(d) - 1) * 3) MONTHS
AS "last day of previous quarter 2"
FROM (VALUES
CURRENT DATE
, DATE('2008-01-01')
, DATE('2008-03-31')
, DATE('2008-04-01')
, DATE('2008-07-31')
, DATE('2008-09-30')
, DATE('2008-10-01')
, DATE('2008-12-31')
) D(d)
;
------------------------------------------------------------------------------
D last day of previous quarter 1 last day of previous quarter
2
---------- ------------------------------
------------------------------
2008-10-29 2008-09-30
2008-09-30
2008-01-01 2007-12-31
2007-12-31
2008-03-31 2007-12-31
2007-12-31
2008-04-01 2008-03-31
2008-03-31
2008-07-31 2008-06-30
2008-06-30
2008-09-30 2008-06-30
2008-06-30
2008-10-01 2008-09-30
2008-09-30
2008-12-31 2008-09-30
2008-09-30
8 record(s) selected.