해당 달을 기준으로 달력 만드는 쿼리.

WITH T AS
(SELECT TO_DATE('201309', 'yyyymm') YM FROM DUAL)
SELECT *
FROM   (
           SELECT MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '1', LEVEL)) SUN
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '2', LEVEL)) MON
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '3', LEVEL)) TUE
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '4', LEVEL)) WED
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '5', LEVEL)) THU
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '6', LEVEL)) FRI
                , MIN(DECODE(TO_CHAR(YM + LEVEL - 1, 'D'), '7', LEVEL)) SAT
           FROM   T
           CONNECT BY
                  LEVEL <= LAST_DAY(YM) - YM + 1
           GROUP BY
                  TRUNC(YM + LEVEL, 'IW')
           ORDER BY
                  SAT
        )