ORA-14759 SET INTERVAL is not legal on this table

SQL> alter table ldbo.TBLSNPRISKDETAILS set INTERVAL (NUMTOYMINTERVAL(1,'MONTH')
);
alter table ldbo.TBLSNPRISKDETAILS set INTERVAL (NUMTOYMINTERVAL(1,'MONTH'))
*
ERROR at line 1:
ORA-14759: SET INTERVAL is not legal on this table.


reason:
PARTITION SAUDA_MAX values LESS THAN (maxvalue)  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M )


 STORAGE(INITIAL 10000M NEXT 1000M)
  TABLESPACE "USR"
  PARTITION BY RANGE ("DSAUDADATE")
(
PARTITION SAUDA_APR values LESS THAN (TO_DATE('01-MAY-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_MAY values LESS THAN (TO_DATE('01-JUN-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_JUN values LESS THAN (TO_DATE('01-JUL-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_JUL values LESS THAN (TO_DATE('01-AUG-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_AUG values LESS THAN (TO_DATE('01-SEP-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_SEP values LESS THAN (TO_DATE('01-OCT-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_OCT values LESS THAN (TO_DATE('01-NOV-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_NOV values LESS THAN (TO_DATE('01-DEC-2015','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_DEC values LESS THAN (TO_DATE('01-JAN-2016','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_JAN values LESS THAN (TO_DATE('01-FEB-2016','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_FEB values LESS THAN (TO_DATE('01-MAR-2016','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_MAR values LESS THAN (TO_DATE('01-APR-2016','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M ),
PARTITION SAUDA_MAX values LESS THAN (maxvalue)  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M )
);