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

Timestamp Operators

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

Operator	Description	Example	Result
+	addition of an INTERVAL	TIMESTAMP '1992-03-22 01:02:03' + INTERVAL 5 DAY	1992-03-27 01:02:03
-	subtraction of TIMESTAMPs	TIMESTAMP '1992-03-27' - TIMESTAMP '1992-03-22'	INTERVAL 5 DAY
-	subtraction of an INTERVAL	TIMESTAMP '1992-03-27 01:02:03' - INTERVAL 5 DAY'	1992-03-22 01:02:03

Timestamp Functions

The table below shows the available scalar functions for TIMESTAMP types.

Function	Description	Example	Result
age(timestamp, timestamp)	Subtract arguments, resulting in the time difference between the two timestamps	age(TIMESTAMP '2001-04-10', TIMESTAMP '1992-09-20')	8 years 6 mons 20 days
age(timestamp)	Subtract from current_date	age(TIMESTAMP '1992-09-20')	26 years 9 mons 9 days
century(timestamp)	Extracts the century of a timestamp	century(TIMESTAMP '1992-03-22')	20
current_timestamp	Current date and time (start of current transaction)
date_diff(part, startdate, enddate)	The number of partition boundaries between the timestamps	date_diff('hour', TIMESTAMP '1992-09-30 23:59:59', TIMESTAMP '1992-10-01')	1
date_part(part, timestamp)	Get subfield (equivalent to extract)	date_part('minute', TIMESTAMP '1992-09-20 20:38:40')	38
date_trunc(part, timestamp)	Truncate to specified precision	date_trunc('hour', TIMESTAMP '1992-09-20 20:38:40')	1992-09-20 20:00:00
day(timestamp)	Extracts the day of a timestamp	dayname(TIMESTAMP '1992-03-22')	Sunday
dayname(timestamp)	The (English) name of the weekday	day(TIMESTAMP '1992-03-22')	22
dayofweek(timestamp)	Extracts the day of the week of a timestamp (0-6, 0 = Sunday, 6 = Saturday)	dayofweek(TIMESTAMP '1992-03-22')	0
dayofyear(timestamp)	Extracts the day of the year of a timestamp (1-366)	dayofyear(TIMESTAMP '1992-03-22')	81
decade(timestamp)	Extracts the decade of a timestamp	decade(TIMESTAMP '1992-03-22')	199
epoch(timestamp)	Extracts the epoch of a timestamp in seconds	epoch(TIMESTAMP '1992-03-22')	701222400
epoch_ms(ms)	Converts ms since epoch to a timestamp	epoch_ms(701222400000)	1992-03-22 00:00:00
extract(field from timestamp)	Get subfield from a timestamp	extract('hour' FROM TIMESTAMP '1992-09-20 20:38:48')	20
greatest(timestamp, timestamp)	The later of two timestamps	least(TIMESTAMP '1992-09-20 20:38:48', TIMESTAMP '1992-03-22 01:02:03.1234')	1992-09-20 20:38:48
hour(timestamp)	Extracts the hour component of a timestamp	hour(TIMESTAMP '1992-03-22 01:02:03.1234')	1
isodow(timestamp)	Extracts the ISO day of the week of a timestamp (1-7, 1 = Monday, 7 = Sunday)	isodow(TIMESTAMP '1992-03-22')	7
last_day(timestamp)	The last day of the month.	last_day(TIMESTAMP '1992-03-22 01:02:03.1234')	1992-03-31
least(timestamp, timestamp)	The earlier of two timestamps	least(TIMESTAMP '1992-09-20 20:38:48', TIMESTAMP '1992-03-22 01:02:03.1234')	1992-03-22 01:02:03.1234
microsecond(timestamp)	Extracts the sub-minute component of a timestamp in microseconds	microsecond(TIMESTAMP '1992-03-22 01:02:03.1234')	3123400
millisecond(timestamp)	Extracts the sub-minute component of a timestamp in milliseconds	millisecond(TIMESTAMP '1992-03-22 01:02:03.1234')	3123
millenium(timestamp)	Extracts the millenium of a timestamp	millenium(TIMESTAMP '1992-03-22')	2
minute(timestamp)	Extracts the minute component of a timestamp	minute(TIMESTAMP '1992-03-22 01:02:03.1234')	2
month(timestamp)	Extracts the month of a timestamp	month(TIMESTAMP '1992-03-22')	3
monthname(timestamp)	The (English) name of the month.	monthname(TIMESTAMP '1992-09-20')	March
now()	Current date and time (start of current transaction)
quarter(timestamp)	Extracts the quarter of a timestamp	quarter(TIMESTAMP '1992-03-22')	1
second(timestamp)	Extracts the second component of a timestamp	second(TIMESTAMP '1992-03-22 01:02:03.1234')	3
strftime(timestamp, format)	Converts timestamp to string according to the format string	strftime(timestamp '1992-01-01 20:38:40', '%a, %-d %B %Y - %I:%M:%S %p')	Wed, 1 January 1992 - 08:38:40 PM
strptime(text, format)	Converts string to timestamp according to the format string	strptime('Wed, 1 January 1992 - 08:38:40 PM', '%a, %-d %B %Y - %I:%M:%S %p')	1992-01-01 20:38:40
to_timestamp(sec)	Converts sec since epoch to a timestamp	to_timestamp(701222400)	1992-03-22 00:00:00
week(timestamp)	Extracts the week number of a timestamp (1-53)	week(TIMESTAMP '1992-03-22')	12
year(timestamp)	Extracts the year of a timestamp	year(TIMESTAMP '1992-03-22')	1992

Timestamp Table Functions

The table below shows the available scalar functions for TIMESTAMP types.

Function	Description	Example
generate_series(timestamp, timestamp, interval)	Generate a table of timestamps in the closed range, stepping by the interval	range(TIMESTAMP '2001-04-10', TIMESTAMP '2001-04-11', INTERVAL 30 MINUTE)
range(timestamp, timestamp, interval)	Generate a table of timestamps in the half open range, stepping by the interval	range(TIMESTAMP '2001-04-10', TIMESTAMP '2001-04-11', INTERVAL 30 MINUTE)