Date/Time Types

PostgreSQL supports the full set of SQL date and time types.

Tabla 7. PostgreSQL Date/Time Types

timestampfor data containing both date and time8 bytes4713 BCAD 14650011 microsec / 14 digits
intervalfor time intervals12 bytes-178000000 years178000000 years1 mircosecond
datefor data containing only dates4 bytes4713 BC32767 AD1 day
timefor data containing only times of the day4 bytes00:00:00.0023:59:59.991 microsecond


To ensure compatibility to earlier versions of PostgreSQL we also continue to provide datetime (equivalent to timestamp) and timespan (equivalent to interval). The types abstime and reltime are lower precision types which are used internally. You are discouraged from using any of these types in new applications and move any old ones over when appropriate. Any or all of these type might disappear in a future release.

Date/Time Input

Date and time input is accepted in almost any reasonable format, including ISO-compatible, SQL-compatible, traditional Postgres, and others. The ordering of month and day in date input can be ambiguous, therefore a setting exists, to specify how it should be interpreted. The command SET DateStyle TO 'US' or SET DateStyle TO 'NonEuropean' specifies the variant "month before day", the command SET DateStyle TO 'European' sets the variant "day before month". The former is the default.

See ayuda de fecha/hora for the exact parsing rules of date/time input and for the recognized time zones.

Remember that any date or time input needs to be enclosed into single quotes, like text strings.


The following are possible inputs for the date type.

Tabla 8. PostgreSQL Date Input

January 8, 1999Unambiguous
1999-01-08ISO-8601 format, preferred
1/8/1999US; read as August 1 in European mode
8/1/1999European; read as August 1 in US mode
1/18/1999US; read as January 18 in any mode
1999.008Year and day of year
19990108ISO-8601 year, month, day
990108ISO-8601 year, month, day
1999.008Year and day of year
99008Year and day of year
January 8, 99 BCYear 99 before the common era

Tabla 9. PostgreSQL Month Abbreviations

SeptemberSep, Sept


The month May has no explicit abbreviation, for obvious reasons.

Tabla 10. PostgreSQL Day of Week Abbreviations

TuesdayTue, Tues
WednesdayWed, Weds
ThursdayThu, Thur, Thurs


The following are valid time inputs.

Tabla 11. PostgreSQL Time Input

04:05 AMSame as 04:05; AM does not affect value
04:05 PMSame as 16:05; input hour must be <= 12
zSame as 00:00:00
zuluSame as 00:00:00
allballsSame as 00:00:00


Valid input for the timestamp type consists of a concatenation of a date and a time, followed by an optional AD or BC, followed by an optional time zone. (See below.) Thus

1999-01-08 04:05:06 -8:00
is a valid timestamp value, which is ISO-compliant. In addition, the wide-spread format
January 8 04:05:06 1999 PST
is supported.

Tabla 12. PostgreSQL Time Zone Input

Time ZoneDescription
PSTPacific Standard Time
-8:00ISO-8601 offset for PST
-800ISO-8601 offset for PST
-8ISO-8601 offset for PST


intervals can be specified with the following syntax:

  Quantity Unit [Quantity Unit...] [Direction]
@ Quantity Unit [Direction]
where: Quantity is ..., -1, 0, 1, 2, ...; Unit is second, minute, hour, day, week, month, year, decade, century, millenium, or abbreviations or plurals of these units; Direction can be ago or empty.

Special values

The following SQL-compatible functions can be used as date or time input for the corresponding datatype: CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP.

PostgreSQL also supports several special constants for convenience.

Tabla 13. PostgresSQL Special Date/Time Constants

currentCurrent transaction time, deferred
epoch1970-01-01 00:00:00+00 (Unix system time zero)
infinityLater than other valid times
-infinityEarlier than other valid times
invalidIllegal entry
nowCurrent transaction time
todayMidnight today
tomorrowMidnight tomorrow
yesterdayMidnight yesterday
'now' is resolved when the value is inserted, 'current' is resolved everytime the value is retrieved. So you probably want to use 'now' in most applications. (Of course you really want to use CURRENT_TIMESTAMP, which is equivalent to 'now'.)

Date/Time Output

Output formats can be set to one of the four styles ISO-8601, SQL (Ingres), traditional Postgres, and German, using the SET DateStyle. The default is the ISO format.

Tabla 14. PostgreSQL Date/Time Output Styles

Style SpecificationDescriptionExample
'ISO'ISO-8601 standard1997-12-17 07:37:16-08
'SQL'Traditional style12/17/1997 07:37:16.00 PST
'Postgres'Original styleWed Dec 17 07:37:16 1997 PST
'German'Regional style17.12.1997 07:37:16.00 PST

The output of the date and time styles is of course only the date or time part in accordance with the above examples

The SQL style has European and non-European (US) variants, which determines whether month follows day or vica versa. (See also above at Date/Time Input, how this setting affects interpretation of input values.)

Tabla 15. PostgreSQL Date Order Conventions

Style SpecificationExample 
European17/12/1997 15:37:16.00 MET 
US12/17/1997 07:37:16.00 PST 

interval output looks like the input format, expect that units like week or century are converted to years and days. In ISO mode the output looks like

[ Quantity Units [ ... ] ] [ Days ] Hours:Minutes [ ago ]

There are several ways to affect the appearance of date/time types:

Time Zones

PostgreSQL endeavors to be compatible with SQL92 definitions for typical usage. However, the SQL92 standard has an odd mix of date and time types and capabilities. Two obvious problems are:

Time zones in the real world can have no meaning unless associated with a date as well as a time since the offset may vary through the year with daylight savings time boundaries.

To address these difficulties, PostgreSQL associates time zones only with date and time types which contain both date and time, and assumes local time for any type containing only date or time. Further, time zone support is derived from the underlying operating system time zone capabilities, and hence can handle daylight savings time and other expected behavior.

PostgreSQL obtains time zone support from the underlying operating system for dates between 1902 and 2038 (near the typical date limits for Unix-style systems). Outside of this range, all dates are assumed to be specified and used in Universal Coordinated Time (UTC).

All dates and times are stored internally in Universal UTC, alternately known as Greenwich Mean Time (GMT). Times are converted to local time on the database server before being sent to the client frontend, hence by default are in the server time zone.

There are several ways to affect the time zone behavior:

If an invalid time zone is specified, the time zone becomes GMT (on most systems anyway).


If the compiler option USE_AUSTRALIAN_RULES is set then EST refers to Australia Eastern Std Time, which has an offset of +10:00 hours from UTC.


PostgreSQL uses Julian dates for all date/time calculations. They have the nice property of correctly predicting/calculating any date more recent than 4713BC to far into the future, using the assumption that the length of the year is 365.2425 days.

Date conventions before the 19th century make for interesting reading, but are not consistant enough to warrant coding into a date/time handler.