ORA-01843:

Question

CREATE TABLE TEST(V_DATE TIMESTAMP)
ALTER TABLE TEST MODIFY V_DATE DEFAULT SYSDATE
INSERT INTO TEST V_DATE VALUES(SYSDATE)
SELECT TO_DATE(V_DATE,'mm/dd/yyyy HH24:mi') FROM TEST
ORA-01843: not a valid month

Answer 1

Try this.
--First Run this and check the format
SQL> select * from nls_database_parameters;
Like:-
NLS_TIMESTAMP_FORMAT           DD-MON-RR HH.MI.SSXFF AM
--You are using datatype in timestamp, so use to_timestamp to convert the static string to timestamp value
SQL> select TO_timestamp(v_date,'DD-MON-RR HH.MI.SSXFF AM') time_on from test
Like:-
TIME_ON
24-JUN-13 11.20.42.000000 AM
--Then use to_char to your desire ouput:-
select to_char(to_timestamp(v_date,'DD-MON-RR HH.MI.SSXFF AM'),'mm/dd/yyyy HH24:mi') time_on from test
Like:-
TIME_ON
06/24/2013 11:20
Thanks!