This section describes functions and operators for examining and manipulating date values.

Date Operators

The table below shows the available mathematical operators for DATE types.

Operator	Description	Example	Result
+	addition of days (integers)	DATE '1992-03-22' + 5	1992-03-27
+	addition of an INTERVAL	DATE '1992-03-22' + INTERVAL 5 DAY	1992-03-27
-	subtraction of DATEs	DATE '1992-03-27' - DATE '1992-03-22'	5
-	subtraction of an INTERVAL	DATE '1992-03-27' - INTERVAL 5 DAY'	1992-03-22

Date Functions

The table below shows the available functions for DATE types. Dates can also be manipulated with the timestamp functions through type promotion.

Function	Description	Example	Result
current_date	Current date (at start of current transaction)
date_diff(part, startdate, , enddate)	The number of partition boundaries between the dates	date_diff('month', DATE '1992-09-15', DATE '1992-11-14')	2
date_part(part, date)	Get the subfield (equivalent to extract)	date_part('year', DATE '1992-09-20')	1992
date_sub(part, startdate, , enddate)	The number of complete partitions between the dates	date_sub('month', DATE '1992-09-15', DATE '1992-11-14')	1
date_trunc(part, date)	Truncate to specified precision	date_trunc('month', DATE '1992-03-07')	1992-03-01
dayname(date)	The (English) name of the weekday.	monthname(DATE '1992-09-20')	Sunday
extract(part from date)	Get subfield from a date	extract('year' FROM DATE '1992-09-20')	1992
greatest(date, date)	The later of two dates	greatest(DATE '1992-09-20', DATE '1992-03-07')	1992-09-20
last_day(date)	The last day of the month.	last_day(DATE '1992-09-20')	1992-09-30
least(date, date)	The earlier of two dates	least(DATE '1992-09-20', DATE '1992-03-07')	1992-03-07
monthname(date)	The (English) name of the month.	monthname(DATE '1992-09-20')	September
strftime(date, format)	Converts a date to a string according to the format string	strftime(date '1992-01-01', '%a, %-d %B %Y')	Wed, 1 January 1992