DATE_PART function

DATE_PART extracts date part values from an expression. DATE_PART is a synonym of the PGDATE_PART function.

Syntax

DATE_PART ( datepart, {date|timestamp} )

Arguments

datepart

The specific part of the date value (year, month, or day, for example) that the function operates on. For more information, see Date parts for date or timestamp functions.

{date|timestamp}

A date or timestamp column or an expression that implicitly converts to a date or timestamp. The expression must be a date or timestamp expression that contains the specified date part.

Return type

DOUBLE

Examples

The following example applies the DATE_PART function to a column in a table.

select date_part(w, listtime) as weeks, listtime
from listing where listid=10;

weeks |      listtime
------+---------------------
 25   | 2008-06-17 09:44:54
(1 row)

You can name date parts in full or abbreviate them; in this case, w stands for weeks.

The day of week date part returns an integer from 0-6, starting with Sunday. Use DATE_PART with dow (DAYOFWEEK) to view events on a Saturday.

select date_part(dow, starttime) as dow,
starttime from event
where date_part(dow, starttime)=6
order by 2,1;

 dow |      starttime
-----+---------------------
   6 | 2008-01-05 14:00:00
   6 | 2008-01-05 14:00:00
   6 | 2008-01-05 14:00:00
   6 | 2008-01-05 14:00:00
...
(1147 rows)

The following example applies the DATE_PART function to a literal date value.

select date_part(minute, '2009-01-01 02:08:01');

pgdate_part
-------------
8
(1 row)

The default column name for the DATE_PART function is PGDATE_PART.