CREATE TABLE SOLN_ITEM_HIST
(
  ORDERNUMBER    VARCHAR2(50 BYTE) NOT NULL,
  M_ID           NUMBER  NOT NdULL,
  MODIFIED_ON    DATE   NOT NULL,
  MODIFIED_BY    VARCHAR2(100 BYTE) NOT NULL
)
PARTITION BY RANGE (MODIFIED_ON) 
( PARTITION P1_ORDER_ITEM_DATA VALUES LESS THAN 
      (TO_DATE(' 2011-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
  PARTITION VALUES LESS THAN 
  (TO_DATE(' 2012-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) )

alter table SOLN_ITEM_HIST drop partition for(to_date('01/01/2012','mm/dd/yyyy'));

 PARTITION_NAME  HIGH_VALUE
SYS_P48163       TO_DATE(' 2012-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')

SQL> create table t (val integer) partition by range (val) 
  2  (partition p1 values less than (100),
  3  partition p2 values less than (maxvalue));

Table created.

SQL> insert into t values (100);

1 row created.

SQL> select * from t partition(p1);

no rows selected

SQL> select * from t partition(p2);
       VAL
----------
       100

1 row selected.

CREATE TABLE SOLN_ITEM_HIST
(
  ORDERNUMBER    VARCHAR2(50 BYTE) NOT NULL,
  M_ID           NUMBER  NOT NdULL,
  MODIFIED_ON    DATE   NOT NULL,
  MODIFIED_BY    VARCHAR2(100 BYTE) NOT NULL
)
PARTITION BY RANGE (MODIFIED_ON)
INTERVAL(NUMTOYMINTERVAL(1, 'MONTH'))
(PARTITION P1_ORD_HIST VALUES LESS THAN (TO_DATE(' 1900-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
 PARTITION VALUES LESS THAN (TO_DATE(' 2012-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))),  
 PARTITION VALUES LESS THAN (TO_DATE(' 2012-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')),
 PARTITION VALUES LESS THAN (TO_DATE(' 2012-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) )

alter table SOLN_ITEM_HIST drop partition for(to_date('01/01/2012','mm/dd/yyyy'));