Ontvang de eerste dag van de week van het weeknummer

probeer dit:

select next_day(max(d), 'sun') requested_sun
  from (select to_date('01-01-2012', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
 where to_char(d, 'ww') = 49-1;

stel gewoon je jaartal in to_date('01-01-2012' en weeknummer-1 49-1 zoals van toepassing.

de zondag in de 49e week van 2008?

SQL> select next_day(max(d), 'sun') requested_sun
  2    from (select to_date('01-01-2008', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
  3   where to_char(d, 'ww') = 49-1;

REQUESTED
---------
07-DEC-08

en 2012

SQL> select next_day(max(d), 'sun') requested_sun
  2    from (select to_date('01-01-2012', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
  3   where to_char(d, 'ww') = 49-1;

REQUESTED
---------
02-DEC-12