WITH t AS
(
SELECT TO_DATE('201406', 'yyyymm') + LEVEL - 1 dt
  FROM dual
 CONNECT BY LEVEL <= 70
)
SELECT dt
     , CEIL( ( NEXT_DAY(dt-1, 4)
             - NEXT_DAY(TRUNC(NEXT_DAY(dt-1, 4), 'mm')-1, 4)
             + 1
             ) / 7) w
  FROM t
;

마농님 감사드립니다. 휴가 복귀 후 적용해보겠습니다.