Oracle Query to produce UNIX cal command like calendar

break on month skip 1
set linesize 20
column month 20
select lpad( Month, 20-(20-length(month))/2 ) month,
       "Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"
  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))) "Su",
       max(decode(to_char(dt,'d'),'2',lpad(to_char(dt,'fmdd'),2))) "Mo",
       max(decode(to_char(dt,'d'),'3',lpad(to_char(dt,'fmdd'),2))) "Tu",
       max(decode(to_char(dt,'d'),'4',lpad(to_char(dt,'fmdd'),2))) "We",
       max(decode(to_char(dt,'d'),'5',lpad(to_char(dt,'fmdd'),2))) "Th",
       max(decode(to_char(dt,'d'),'6',lpad(to_char(dt,'fmdd'),2))) "Fr",
       max(decode(to_char(dt,'d'),'7',lpad(to_char(dt,'fmdd'),2))) "Sa"
  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)