cal in oracle

MM MON

TUE

WED

THR

FRI

SAT

SUN

01

1 mat1:1-2:12

2 mat2:13-3:6

3 mat3:7-4:11

4 mat4:12-25

5 mat5:1-26

6 mat5:27-48

01 7 mat6:1-24

8 mat6:25-7:14 9 mat7:15-29

10 mat8:1-17

11 mat8:18-34

12 mat9:1-17

13 mat9:18-38

01 14 mat10:1-23

15 mat10:24-11:6 16 mat11:7-30

17 mat12:1-21

18 mat12:22-45 19 mat12:46-13:2320 mat13:24-46

01 21 mat13:47-14:12 22 mat14:13-36 23 mat15:1-28

24 mat15:29-16:1225 mat16:13-17:9 26 mat17:10-27 27 mat18:1-20

01 28 mat18:21-19:12 29 mat19:13-30 30 mat20:1-28

31 mat20:29-21:22

02

1 mat21:23-46

2 mat22:1-33

3 mat22:34-23:12

02 4 mat23:13-39

5 mat24:1-28

6 mat24:29-51

7 mat25:1-30

8 mat25:31-26:13 9 mat26:14-46

10 mat26:47-68

02 11 mat26:69-27:14 12 mat27:15-31 13 mat27:32-66 14 mat28:1-20

15 mak1:1-28

16 mak1:29-2:12 17 mak2:13-3:63

02 18 mak3:7-30

19 mak3:31-4:25 20 mak4:26-5:20 21 mak5:21-43

22 mak6:1-29

23 mak6:30-56

24 mak7:1-23

02 25 mak7:24-8:10 26 mak8:11-38

27 mak9:1-29

28 mak9:30-10:12

with as table named cal in two column (mon & day) plus todo column (pr),
how to build a calendar in pure Oracle SQL?

select mm, mon, tue, wed, thr, fri, sat, sun from (
select mm,
lag(dd, 6) over ( partition by mm order by dd ) mon_flag,
lag(todo, 6) over ( partition by mm order by dd ) mon,
lag(todo, 5) over ( partition by mm order by dd ) tue,
lag(todo, 4) over ( partition by mm order by dd ) wed,
lag(todo, 3) over ( partition by mm order by dd ) thr,
lag(todo, 2) over ( partition by mm order by dd ) fri,
lag(todo, 1) over ( partition by mm order by dd ) sat,
ot sun,
dd sun_flag
from (
with dml as (
select trunc(sysdate,'yy')+level-1 dd from dual
connect by level<=add_months(sysdate,12)-sysdate
)
select dd, ot, to_char(dd, 'MM') mm from dml
natural join (
select to_date(mon||'-'||day, 'mm-dd') dd,
day||' '||pr todo from cal
)
union all
select null, null, to_char(dd, 'MM') mm from dml
)
)
where to_char(sun_flag,'d')=1 or to_char(mon_flag,'d')=2
/