Oracle - Date Datatype

Use the DATE data type to store point-in-time values (dates and times) in a table. An application that specifies the time for a job might use the DATE data type.

The DATE data type stores:

• the century,
• year,
• month,
• day,
• hours,
• minutes,
• and seconds.

The valid date range is from January 1, 4712 BC to December 31, 9999 AD.

Use the TIMESTAMP data type to store values that are precise to fractional seconds. An application that must decide which of two events occurred first might use TIMESTAMP.

The formatting of a date is controlled by the following parameters :

• Oracle Database - NLS_DATE_LANGUAGE
• Oracle Database - NLS_DATE_FORMAT

Snippet with the TO_CHAR function to give a specific format:

TO_CHAR(COLUMN_WITH_DATE_DATATYPE, 'YYYY/MM/DD HH24:MI:SS'),

• Datetime Format Elements

select
  (End_Date - Start_Date)*24*60*60 diff_in_secondes
from
  your_table

select TO_DATE('20141021 15:34:10','YYYYMMDD HH24:MI:SS')+ 
+(1)          *9 -- Day
+(1/24)       *9 -- Hour
+(1/24/60)    *9 -- Minutes
+(1/24/60/60) *9 -- Seconden
from dual;

• Datetime Format Elements