Grouping by weekday

Question

Hi,
How can we show details and group by week number for a set of data when the custom week begins Saturday and ends Friday?
For example, the table has data as follows:
Date Hrs Weekday
12/01/2007 8 Saturday
12/02/2007 8 Sunday
12/03/2007 11 Monday
12/04/2007 0 Tuesday
12/05/2007 9 Wednesday
12/06/2007 8 Thursday
12/07/2007 8 Friday
12/08/2007 8 Saturday
12/09/2007 9 Sunday
12/10/2007 8 Monday
12/11/2007 0 Tuesday
12/12/2007 0 Wednesday
12/13/2007 12 Thursday
12/14/2007 8 Friday
12/15/2007 9 Saturday
In Oracle Reports, if I group it by week number using
to_char(to_date(:p_date,'DD-MON-RRRR'),'WW') within the query, I get the week no of the year and begins from Monady of the date range.
So it gives my summary like
Week1 16
Week2 53
Week3 37
I wanted the report to show it as
Week1 52 (from 12/01/2007 to 12/07/2007)
Week2 45 (from 12/08/2007 to 12/14/2007)
Week3 9 (for 12/15/2007 and beyond ...
Can someone shed some light on how to achieve it without using any temporary table and within the SQL quey for use in Oracle Reports?
Your valuable inputs is very much appreciated.
Thanks
uds

Answer 1

Thanks for the inputs. I appreciate that. This solution does not serve my purpose and so had to define a small function to accept the reporting date and return the week number of the year after having jacked up as required. Here is the function:
CREATE OR REPLACE FUNCTION fn_user_otl_week_no (
p_start_time IN DATE )
RETURN NUMBER
IS
l_week_no NUMBER;
l_weekday CHAR (30);
BEGIN
SELECT TO_CHAR (TO_DATE (p_start_time, 'DD-MON-RRRR'), 'DAY'),
TO_NUMBER (TO_CHAR (TO_DATE (p_start_time, 'DD-MON-RRRR'), 'WW'))
INTO l_weekday,
l_week_no
FROM DUAL;
IF l_weekday = 'SATURDAY'
THEN
l_week_no := l_week_no + 1;
ELSIF l_weekday = 'SUNDAY'
THEN
l_week_no := l_week_no + 1;
END IF;
RETURN (l_week_no);
EXCEPTION
WHEN OTHERS
THEN
RETURN (0);
END;
In my query, I can send in a date and get back the week of year. The code is self explanatory. The following qry
select to_char(to_date('08-DEC-2007','DD-MON-RRRR'),'WW') wk_of_yr,
gn_otl_week_no('08-DEC-2007') wk_bump from dual
yielded
49 50
For '10-DEC-2007' it yielded
50 50
This is what I had wanted. By this I can group the hrs logged and sum it up for the week from Saturday to the following Friday.
Thanks for all the inputs.
One caveat I faced was that the return value did not get incremented if I declared the variable l_weekday as VARCHAR2(30). But works fine if declared as CHAR(30). Well, this could be some issue with VARCHAR2 vs CHAR; a whole different ballgame altogether.
Thanks
uds