Oracle date format picture ends before converting entire input string

you need to alter session

you can try before insert

 sql : alter session set nls_date_format = 'YYYY-MM-DD HH24:MI:SS'

Perhaps you should check NLS_DATE_FORMAT and use the date string conforming the format. Or you can use to_date function within the INSERT statement, like the following:

insert into visit
values(123456, 
       to_date('19-JUN-13', 'dd-mon-yy'),
       to_date('13-AUG-13 12:56 A.M.', 'dd-mon-yyyy hh:mi A.M.'));

Additionally, Oracle DATE stores date and time information together.

What you're trying to insert is not a date, I think, but a string. You need to use to_date() function, like this:

insert into table t1 (id, date_field) values (1, to_date('20.06.2013', 'dd.mm.yyyy'));