Sample query to build calendar

SELECT LPAD( MONTH, 20-(20-LENGTH(MONTH))/2 ) MONTH,"Sun", "Mon", "Tue",
"Wed", "Thu", "Fri", "Sat"
FROM (SELECT TO_CHAR(dt,'fmMonthfm YYYY') MONTH,TO_CHAR(dt+1,'iw') week,
MAX(DECODE(TO_CHAR(dt,'d'),'1',LPAD(TO_CHAR(dt,'fmdd'),2))) "Sun",
MAX(DECODE(TO_CHAR(dt,'d'),'2',LPAD(TO_CHAR(dt,'fmdd'),2))) "Mon",
MAX(DECODE(TO_CHAR(dt,'d'),'3',LPAD(TO_CHAR(dt,'fmdd'),2))) "Tue",
MAX(DECODE(TO_CHAR(dt,'d'),'4',LPAD(TO_CHAR(dt,'fmdd'),2))) "Wed",
MAX(DECODE(TO_CHAR(dt,'d'),'5',LPAD(TO_CHAR(dt,'fmdd'),2))) "Thu",
MAX(DECODE(TO_CHAR(dt,'d'),'6',LPAD(TO_CHAR(dt,'fmdd'),2))) "Fri",
MAX(DECODE(TO_CHAR(dt,'d'),'7',LPAD(TO_CHAR(dt,'fmdd'),2))) "Sat"
FROM ( SELECT TRUNC(SYSDATE,'y')-1+ROWNUM dt
FROM all_objects
WHERE ROWNUM <= ADD_MONTHS(TRUNC(SYSDATE,'y'),12) - TRUNC(SYSDATE,'y'))
GROUP BY TO_CHAR(dt,'fmMonthfm YYYY'), TO_CHAR( dt+1, 'iw' ))
ORDER BY TO_DATE( MONTH, 'Month YYYY' ), TO_NUMBER(week)