Another datatype is TIMESTAMP which is basically an upgrade of DATE to include fractional seconds and time zone info. There are a couple of interesting variations on TIMESTAMP which are TIMESTAMP WITH TIME ZONE and TIMESTAMP WITH LOCAL TIME ZONE.

TIMESTAMP can contain a value like '01-JAN-2003 04:56:07.890123'
TIMESTAMP WITH TIME ZONE adds a time zone to that, e.g. '01-JAN-2003 04:56:07.890123 GMT'

TIMESTAMP WITH LOCAL TIME ZONE is an interesting one. Timestamp values are converted to reflect the time in different parts of the world. So if I store '01-JAN-2003 04:56:07.890123 GMT' in a French database (GMT+1), it will be stored as '01-JAN-2003 05:56:07.890123' because France is 1 hour ahead of the UK. If this value is subsequently accessed by a computer in Israel which is GMT+2 it will be returned as '01-JAN-2003 06:56:07.890123'. This reflects the fact that '01-JAN-2003 04:56:07.890123 GMT' is equal to '01-JAN-2003 06:56:07.890123' in Israel.

For more brain numbing stuff have a look at the INTERVAL types in the SQL reference.