Perhaps you should check NLS_DATE_FORMAT and use a date string that matches the format. Or you can use the to_date function in an INSERT , as shown below:
insert into visit values(123456, to_date('19-JUN-13', 'dd-mon-yy'), to_date('13-AUG-13 12:56 AM', 'dd-mon-yyyy hh:mi AM'));
In addition, Oracle DATE stores the date and time .
ntalbs
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