As far as my search shows, ORACLE can be picky on dates so this might be what you need to do.
Firstly, check the format of date you have. For example, if you have something like, 2010/01/26:11:00:00AM, then you might want to do following on your cursor execute:
insert into x
values(99, to_date('2010/01/26:11:00:00AM', 'yyyy/mm/dd:hh:mi:ssam'));