Usar:
SELECT TO_CHAR(date1,'MMDDYYYY:HH24:MI:SS') date1,
TO_CHAR(date2,'MMDDYYYY:HH24:MI:SS') date2,
TRUNC(86400*(date2-date1)) - 60*(TRUNC((86400*(date2-date1))/60)) seconds,
TRUNC((86400*(date2-date1))/60) - 60*(TRUNC(((86400*(date2-date1))/60)/60)) minutes,
TRUNC(((86400*(date2-date1))/60)/60) - 24*(TRUNC((((86400*(date2-date1))/60)/60)/24)) hours,
TRUNC((((86400*(date2-date1))/60)/60)/24) days,
TRUNC(((((86400*(date2-date1))/60)/60)/24)/7) weeks
FROM TABLE
Referência:Uma comparação dos tipos de dados DATE e TIMESTAMP da Oracle
