Oracle Dato subtraktion

Brug:

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

Reference:En sammenligning af Oracles DATE- og TIMESTAMP-datatyper