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+$PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.147 2004/08/10 00:55:02 tgl Exp $
-->
<chapter id="datatype">
</tbody>
</tgroup>
</table>
+
+ <para>
+ Refer to <xref linkend="datetime-appendix"> for a list of
+ time zone names that are recognized for input.
+ </para>
</sect3>
<sect3>
<para>
Valid input for the time stamp types consists of a concatenation
- of a date and a time, followed by an optional
- <literal>AD</literal> or <literal>BC</literal>, followed by an
- optional time zone. Thus
+ of a date and a time, followed by an optional time zone,
+ followed by an optional <literal>AD</literal> or <literal>BC</literal>.
+ (Alternatively, <literal>AD</literal>/<literal>BC</literal> can appear
+ before the time zone, but this is not the preferred ordering.)
+ Thus
<programlisting>
1999-01-08 04:05:06
</indexterm>
<para>
- The following <acronym>SQL</acronym>-compatible functions can be
- used as date or time values for the corresponding data type:
- <literal>CURRENT_DATE</literal>, <literal>CURRENT_TIME</literal>,
- <literal>CURRENT_TIMESTAMP</literal>, <literal>LOCALTIME</literal>,
- <literal>LOCALTIMESTAMP</literal>. The latter four accept an
- optional precision specification. (See also <xref
- linkend="functions-datetime-current">.)
- </para>
-
- <para>
- <productname>PostgreSQL</productname> also supports several
+ <productname>PostgreSQL</productname> supports several
special date/time input values for convenience, as shown in <xref
linkend="datatype-datetime-special-table">. The values
<literal>infinity</literal> and <literal>-infinity</literal>
</tgroup>
</table>
+ <para>
+ The following <acronym>SQL</acronym>-compatible functions can also
+ be used to obtain the current time value for the corresponding data
+ type:
+ <literal>CURRENT_DATE</literal>, <literal>CURRENT_TIME</literal>,
+ <literal>CURRENT_TIMESTAMP</literal>, <literal>LOCALTIME</literal>,
+ <literal>LOCALTIMESTAMP</literal>. The latter four accept an
+ optional precision specification. (See also <xref
+ linkend="functions-datetime-current">.) Note however that these are
+ SQL functions and are <emphasis>not</> recognized as data input strings.
+ </para>
+
</sect3>
</sect2>
<para>
<type>interval</type> output looks like the input format, except
that units like <literal>century</literal> or
- <literal>wek</literal> are converted to years and days and that
+ <literal>week</literal> are converted to years and days and
<literal>ago</literal> is converted to an appropriate sign. In
ISO mode the output looks like
<programlisting>
-<optional> <replaceable>quantity</> <replaceable>unit</> <optional> ... </> </> <optional> <replaceable>days</> </> <optional> <replaceable>hours</>:<replaceable>minutes</>:<replaceable>sekunden</> </optional>
+<optional> <replaceable>quantity</> <replaceable>unit</> <optional> ... </> </> <optional> <replaceable>days</> </> <optional> <replaceable>hours</>:<replaceable>minutes</>:<replaceable>seconds</> </optional>
</programlisting>
</para>
Time zones, and time-zone conventions, are influenced by
political decisions, not just earth geometry. Time zones around the
world became somewhat standardized during the 1900's,
- but continue to be prone to arbitrary changes.
- <productname>PostgreSQL</productname> uses your operating
- system's underlying features to provide output time-zone
- support, and these systems usually contain information for only
- the time period 1902 through 2038 (corresponding to the full
- range of conventional Unix system time).
- <type>timestamp with time zone</type> and <type>time with time
- zone</type> will use time zone
- information only within that year range, and assume that times
- outside that range are in <acronym>UTC</acronym>.
- But since time zone support is derived from the underlying operating
- system time-zone capabilities, it can handle daylight-saving time
- and other special behavior.
+ but continue to be prone to arbitrary changes, particularly with
+ respect to daylight-savings rules.
+ <productname>PostgreSQL</productname> currently supports daylight-savings
+ rules over the time period 1902 through 2038 (corresponding to the full
+ range of conventional Unix system time). Times outside that range are
+ taken to be in <quote>standard time</> for the selected time zone, no
+ matter what part of the year they fall in.
</para>
<para>
Although the <type>date</type> type
does not have an associated time zone, the
<type>time</type> type can.
- Time zones in the real world can have no meaning unless
- associated with a date as well as a time
+ Time zones in the real world have little meaning unless
+ associated with a date as well as a time,
since the offset may vary through the year with daylight-saving
time boundaries.
</para>
<listitem>
<para>
The default time zone is specified as a constant numeric offset
- from <acronym>UTC</>. It is not possible to adapt to daylight-saving
- time when doing date/time arithmetic across
+ from <acronym>UTC</>. It is therefore not possible to adapt to
+ daylight-saving time when doing date/time arithmetic across
<acronym>DST</acronym> boundaries.
</para>
</listitem>
recommend <emphasis>not</emphasis> using the type <type>time with
time zone</type> (though it is supported by
<productname>PostgreSQL</productname> for legacy applications and
- for compatibility with other <acronym>SQL</acronym>
- implementations). <productname>PostgreSQL</productname> assumes
+ for compliance with the <acronym>SQL</acronym> standard).
+ <productname>PostgreSQL</productname> assumes
your local time zone for any type containing only date or time.
</para>
<para>
- All dates and times are stored internally in
- <acronym>UTC</acronym>. Times are converted to local time
- on the database server before being sent to the client,
- hence by default are in the server time zone.
+ All timezone-aware dates and times are stored internally in
+ <acronym>UTC</acronym>. They are converted to local time
+ in the zone specified by the <xref linkend="guc-timezone"> configuration
+ parameter before being displayed to the client.
</para>
<para>
- There are several ways to select the time zone used by the server:
+ The <xref linkend="guc-timezone"> configuration parameter can
+ be set in the file <filename>postgresql.conf</>, or in any of the
+ other standard ways described in <xref linkend="runtime-config">.
+ There are also several special ways to set it:
<itemizedlist>
<listitem>
<para>
- The <envar>TZ</envar> environment variable on the server host
- is used by the server as the default time zone, if no other is
- specified.
+ If <varname>timezone</> is not specified in
+ <filename>postgresql.conf</> nor as a postmaster command-line switch,
+ the server attempts to use the value of the <envar>TZ</envar>
+ environment variable as the default time zone. If <envar>TZ</envar>
+ is not defined or is not any of the time zone names known to
+ <productname>PostgreSQL</productname>, the server attempts to
+ determine the operating system's default time zone by checking the
+ behavior of the C library function <literal>localtime()</>. The
+ default time zone is selected as the closest match among
+ <productname>PostgreSQL</productname>'s known time zones.
</para>
</listitem>
<listitem>
<para>
- The <xref linkend="guc-timezone"> configuration parameter can
- be set in the file <filename>postgresql.conf</>.
+ The <acronym>SQL</acronym> command <command>SET TIME ZONE</command>
+ sets the time zone for the session. This is an alternative spelling
+ of <command>SET TIMEZONE TO</> with a more SQL-spec-compatible syntax.
</para>
</listitem>
command to the server upon connection.
</para>
</listitem>
-
- <listitem>
- <para>
- The <acronym>SQL</acronym> command <command>SET TIME ZONE</command>
- sets the time zone for the session.
- </para>
- </listitem>
</itemizedlist>
</para>
- <note>
- <para>
- If an invalid time zone is specified, the time zone becomes
- <acronym>UTC</acronym> (on most systems anyway).
- </para>
- </note>
-
<para>
Refer to <xref linkend="datetime-appendix"> for a list of
available time zones.
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-$PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.41 2004/03/31 16:20:53 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.42 2004/08/10 00:55:03 tgl Exp $
-->
<appendix id="datetime-appendix">
field. Each field is interpreted and either assigned a numeric
value, ignored, or rejected.
The parser contains internal lookup tables for all textual fields,
- including months, days of the week, and time
- zones.
+ including months, days of the week, and time zones.
</para>
<para>
<para>
If BC has been specified, negate the year and add one for
internal storage. (There is no year zero in the Gregorian
- calendar, so numerically 1 BC becomes year
- zero.)
+ calendar, so numerically 1 BC becomes year zero.)
</para>
</step>
<step>
<para>
- If BC was not specified, and if the year field was two digits in length, then
- adjust the year to four digits. If the field is less than 70, then add 2000,
- otherwise add 1900.
+ If BC was not specified, and if the year field was two digits in length,
+ then adjust the year to four digits. If the field is less than 70, then
+ add 2000, otherwise add 1900.
<tip>
<para>
<indexterm>
<primary>time zone</primary>
- <secondary>abbreviations</secondary>
+ <secondary>input abbreviations</secondary>
</indexterm>
<para>
- <xref linkend="datetime-timezone-table"> shows the time zone
+ <xref linkend="datetime-timezone-input-table"> shows the time zone
abbreviations recognized by <productname>PostgreSQL</productname>
- in date/time input values.
- <productname>PostgreSQL</productname> uses internal tables
- for time zone input decoding, since there is no standard
- operating system interface to provide access to general,
- cross-time zone information. The underlying operating system
- <emphasis>is</emphasis> used to provide time zone information for
- <emphasis>output</emphasis>, however.
- </para>
-
- <para>
- Keep in mind also that the time zone names
- recognized by <command>SET TIMEZONE</> are operating-system
- dependent and may have little to do with <xref
- linkend="datetime-timezone-table">. For example, some systems
- recognize values like <literal>'Europe/Rome'</> in <command>SET
- TIMEZONE</>.
+ in date/time input values. Note that these names are <emphasis>not</>
+ used for date/time output --- display is driven by the currently
+ selected <xref linkend="guc-timezone"> parameter setting. (It is
+ likely that future releases will make some use of <varname>timezone</>
+ for input as well.)
</para>
<para>
these might differ.
</para>
- <table id="datetime-timezone-table">
- <title>Time Zone Abbreviations</title>
+ <table id="datetime-timezone-input-table">
+ <title>Time Zone Abbreviations for Input</title>
<tgroup cols="3">
<thead>
<row>
</formalpara>
<table id="datetime-oztz-table">
- <title>Australian Time Zone Abbreviations</title>
+ <title>Australian Time Zone Abbreviations for Input</title>
<tgroup cols="3">
<thead>
<row>
</tgroup>
</table>
+ <indexterm>
+ <primary>time zone</primary>
+ <secondary>configuration names</secondary>
+ </indexterm>
+
+ <para>
+ <xref linkend="datetime-timezone-set-table"> shows the time zone
+ names recognized by <productname>PostgreSQL</productname> as valid
+ settings for the <xref linkend="guc-timezone"> parameter. Note that
+ these names are conceptually as well as practically different from
+ the names shown in <xref linkend="datetime-timezone-input-table">:
+ most of these names imply a local daylight-savings time rule, whereas
+ the former names each represent just a fixed offset from UTC.
+ </para>
+
+ <para>
+ In many cases there are several equivalent names for the same zone.
+ These are listed on the same line. The table is primarily sorted
+ by the name of the principal city of the zone.
+ </para>
+
+ <table id="datetime-timezone-set-table">
+ <title>Time Zone Names for Setting <varname>timezone</></title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry>Time Zone</entry>
+ </row>
+ </thead>
+<tbody>
+ <row>
+ <entry>Africa/Abidjan</entry>
+ </row>
+ <row>
+ <entry>Africa/Accra</entry>
+ </row>
+ <row>
+ <entry>Africa/Addis_Ababa</entry>
+ </row>
+ <row>
+ <entry>Africa/Algiers</entry>
+ </row>
+ <row>
+ <entry>Africa/Asmera</entry>
+ </row>
+ <row>
+ <entry>Africa/Bamako</entry>
+ </row>
+ <row>
+ <entry>Africa/Bangui</entry>
+ </row>
+ <row>
+ <entry>Africa/Banjul</entry>
+ </row>
+ <row>
+ <entry>Africa/Bissau</entry>
+ </row>
+ <row>
+ <entry>Africa/Blantyre</entry>
+ </row>
+ <row>
+ <entry>Africa/Brazzaville</entry>
+ </row>
+ <row>
+ <entry>Africa/Bujumbura</entry>
+ </row>
+ <row>
+ <entry>Africa/Cairo Egypt</entry>
+ </row>
+ <row>
+ <entry>Africa/Casablanca</entry>
+ </row>
+ <row>
+ <entry>Africa/Ceuta</entry>
+ </row>
+ <row>
+ <entry>Africa/Conakry</entry>
+ </row>
+ <row>
+ <entry>Africa/Dakar</entry>
+ </row>
+ <row>
+ <entry>Africa/Dar_es_Salaam</entry>
+ </row>
+ <row>
+ <entry>Africa/Djibouti</entry>
+ </row>
+ <row>
+ <entry>Africa/Douala</entry>
+ </row>
+ <row>
+ <entry>Africa/El_Aaiun</entry>
+ </row>
+ <row>
+ <entry>Africa/Freetown</entry>
+ </row>
+ <row>
+ <entry>Africa/Gaborone</entry>
+ </row>
+ <row>
+ <entry>Africa/Harare</entry>
+ </row>
+ <row>
+ <entry>Africa/Johannesburg</entry>
+ </row>
+ <row>
+ <entry>Africa/Kampala</entry>
+ </row>
+ <row>
+ <entry>Africa/Khartoum</entry>
+ </row>
+ <row>
+ <entry>Africa/Kigali</entry>
+ </row>
+ <row>
+ <entry>Africa/Kinshasa</entry>
+ </row>
+ <row>
+ <entry>Africa/Lagos</entry>
+ </row>
+ <row>
+ <entry>Africa/Libreville</entry>
+ </row>
+ <row>
+ <entry>Africa/Lome</entry>
+ </row>
+ <row>
+ <entry>Africa/Luanda</entry>
+ </row>
+ <row>
+ <entry>Africa/Lubumbashi</entry>
+ </row>
+ <row>
+ <entry>Africa/Lusaka</entry>
+ </row>
+ <row>
+ <entry>Africa/Malabo</entry>
+ </row>
+ <row>
+ <entry>Africa/Maputo</entry>
+ </row>
+ <row>
+ <entry>Africa/Maseru</entry>
+ </row>
+ <row>
+ <entry>Africa/Mbabane</entry>
+ </row>
+ <row>
+ <entry>Africa/Mogadishu</entry>
+ </row>
+ <row>
+ <entry>Africa/Monrovia</entry>
+ </row>
+ <row>
+ <entry>Africa/Nairobi</entry>
+ </row>
+ <row>
+ <entry>Africa/Ndjamena</entry>
+ </row>
+ <row>
+ <entry>Africa/Niamey</entry>
+ </row>
+ <row>
+ <entry>Africa/Nouakchott</entry>
+ </row>
+ <row>
+ <entry>Africa/Ouagadougou</entry>
+ </row>
+ <row>
+ <entry>Africa/Porto-Novo</entry>
+ </row>
+ <row>
+ <entry>Africa/Sao_Tome</entry>
+ </row>
+ <row>
+ <entry>Africa/Timbuktu</entry>
+ </row>
+ <row>
+ <entry>Africa/Tripoli Libya</entry>
+ </row>
+ <row>
+ <entry>Africa/Tunis</entry>
+ </row>
+ <row>
+ <entry>Africa/Windhoek</entry>
+ </row>
+ <row>
+ <entry>America/Adak America/Atka US/Aleutian</entry>
+ </row>
+ <row>
+ <entry>America/Anchorage SystemV/YST9YDT US/Alaska</entry>
+ </row>
+ <row>
+ <entry>America/Anguilla</entry>
+ </row>
+ <row>
+ <entry>America/Antigua</entry>
+ </row>
+ <row>
+ <entry>America/Araguaina</entry>
+ </row>
+ <row>
+ <entry>America/Aruba</entry>
+ </row>
+ <row>
+ <entry>America/Asuncion</entry>
+ </row>
+ <row>
+ <entry>America/Bahia</entry>
+ </row>
+ <row>
+ <entry>America/Barbados</entry>
+ </row>
+ <row>
+ <entry>America/Belem</entry>
+ </row>
+ <row>
+ <entry>America/Belize</entry>
+ </row>
+ <row>
+ <entry>America/Boa_Vista</entry>
+ </row>
+ <row>
+ <entry>America/Bogota</entry>
+ </row>
+ <row>
+ <entry>America/Boise</entry>
+ </row>
+ <row>
+ <entry>America/Buenos_Aires</entry>
+ </row>
+ <row>
+ <entry>America/Cambridge_Bay</entry>
+ </row>
+ <row>
+ <entry>America/Campo_Grande</entry>
+ </row>
+ <row>
+ <entry>America/Cancun</entry>
+ </row>
+ <row>
+ <entry>America/Caracas</entry>
+ </row>
+ <row>
+ <entry>America/Catamarca</entry>
+ </row>
+ <row>
+ <entry>America/Cayenne</entry>
+ </row>
+ <row>
+ <entry>America/Cayman</entry>
+ </row>
+ <row>
+ <entry>America/Chicago CST6CDT SystemV/CST6CDT US/Central</entry>
+ </row>
+ <row>
+ <entry>America/Chihuahua</entry>
+ </row>
+ <row>
+ <entry>America/Cordoba America/Rosario</entry>
+ </row>
+ <row>
+ <entry>America/Costa_Rica</entry>
+ </row>
+ <row>
+ <entry>America/Cuiaba</entry>
+ </row>
+ <row>
+ <entry>America/Curacao</entry>
+ </row>
+ <row>
+ <entry>America/Danmarkshavn</entry>
+ </row>
+ <row>
+ <entry>America/Dawson</entry>
+ </row>
+ <row>
+ <entry>America/Dawson_Creek</entry>
+ </row>
+ <row>
+ <entry>America/Denver MST7MDT SystemV/MST7MDT US/Mountain America/Shiprock Navajo</entry>
+ </row>
+ <row>
+ <entry>America/Detroit US/Michigan</entry>
+ </row>
+ <row>
+ <entry>America/Dominica</entry>
+ </row>
+ <row>
+ <entry>America/Edmonton Canada/Mountain</entry>
+ </row>
+ <row>
+ <entry>America/Eirunepe</entry>
+ </row>
+ <row>
+ <entry>America/El_Salvador</entry>
+ </row>
+ <row>
+ <entry>America/Ensenada America/Tijuana Mexico/BajaNorte</entry>
+ </row>
+ <row>
+ <entry>America/Fortaleza</entry>
+ </row>
+ <row>
+ <entry>America/Glace_Bay</entry>
+ </row>
+ <row>
+ <entry>America/Godthab</entry>
+ </row>
+ <row>
+ <entry>America/Goose_Bay</entry>
+ </row>
+ <row>
+ <entry>America/Grand_Turk</entry>
+ </row>
+ <row>
+ <entry>America/Grenada</entry>
+ </row>
+ <row>
+ <entry>America/Guadeloupe</entry>
+ </row>
+ <row>
+ <entry>America/Guatemala</entry>
+ </row>
+ <row>
+ <entry>America/Guayaquil</entry>
+ </row>
+ <row>
+ <entry>America/Guyana</entry>
+ </row>
+ <row>
+ <entry>America/Halifax Canada/Atlantic SystemV/AST4ADT</entry>
+ </row>
+ <row>
+ <entry>America/Havana Cuba</entry>
+ </row>
+ <row>
+ <entry>America/Hermosillo</entry>
+ </row>
+ <row>
+ <entry>America/Indiana/Indianapolis America/Indianapolis America/Fort_Wayne EST SystemV/EST5 US/East-Indiana</entry>
+ </row>
+ <row>
+ <entry>America/Indiana/Knox America/Knox_IN US/Indiana-Starke</entry>
+ </row>
+ <row>
+ <entry>America/Indiana/Marengo</entry>
+ </row>
+ <row>
+ <entry>America/Indiana/Vevay</entry>
+ </row>
+ <row>
+ <entry>America/Inuvik</entry>
+ </row>
+ <row>
+ <entry>America/Iqaluit</entry>
+ </row>
+ <row>
+ <entry>America/Jamaica Jamaica</entry>
+ </row>
+ <row>
+ <entry>America/Jujuy</entry>
+ </row>
+ <row>
+ <entry>America/Juneau</entry>
+ </row>
+ <row>
+ <entry>America/Kentucky/Louisville America/Louisville</entry>
+ </row>
+ <row>
+ <entry>America/Kentucky/Monticello</entry>
+ </row>
+ <row>
+ <entry>America/La_Paz</entry>
+ </row>
+ <row>
+ <entry>America/Lima</entry>
+ </row>
+ <row>
+ <entry>America/Los_Angeles PST8PDT SystemV/PST8PDT US/Pacific US/Pacific-New</entry>
+ </row>
+ <row>
+ <entry>America/Maceio</entry>
+ </row>
+ <row>
+ <entry>America/Managua</entry>
+ </row>
+ <row>
+ <entry>America/Manaus Brazil/West</entry>
+ </row>
+ <row>
+ <entry>America/Martinique</entry>
+ </row>
+ <row>
+ <entry>America/Mazatlan Mexico/BajaSur</entry>
+ </row>
+ <row>
+ <entry>America/Mendoza</entry>
+ </row>
+ <row>
+ <entry>America/Menominee</entry>
+ </row>
+ <row>
+ <entry>America/Merida</entry>
+ </row>
+ <row>
+ <entry>America/Mexico_City Mexico/General</entry>
+ </row>
+ <row>
+ <entry>America/Miquelon</entry>
+ </row>
+ <row>
+ <entry>America/Monterrey</entry>
+ </row>
+ <row>
+ <entry>America/Montevideo</entry>
+ </row>
+ <row>
+ <entry>America/Montreal</entry>
+ </row>
+ <row>
+ <entry>America/Montserrat</entry>
+ </row>
+ <row>
+ <entry>America/Nassau</entry>
+ </row>
+ <row>
+ <entry>America/New_York EST5EDT SystemV/EST5EDT US/Eastern</entry>
+ </row>
+ <row>
+ <entry>America/Nipigon</entry>
+ </row>
+ <row>
+ <entry>America/Nome</entry>
+ </row>
+ <row>
+ <entry>America/Noronha Brazil/DeNoronha</entry>
+ </row>
+ <row>
+ <entry>America/North_Dakota/Center</entry>
+ </row>
+ <row>
+ <entry>America/Panama</entry>
+ </row>
+ <row>
+ <entry>America/Pangnirtung</entry>
+ </row>
+ <row>
+ <entry>America/Paramaribo</entry>
+ </row>
+ <row>
+ <entry>America/Phoenix MST SystemV/MST7 US/Arizona</entry>
+ </row>
+ <row>
+ <entry>America/Port-au-Prince</entry>
+ </row>
+ <row>
+ <entry>America/Port_of_Spain</entry>
+ </row>
+ <row>
+ <entry>America/Porto_Acre America/Rio_Branco Brazil/Acre</entry>
+ </row>
+ <row>
+ <entry>America/Porto_Velho</entry>
+ </row>
+ <row>
+ <entry>America/Puerto_Rico SystemV/AST4</entry>
+ </row>
+ <row>
+ <entry>America/Rainy_River</entry>
+ </row>
+ <row>
+ <entry>America/Rankin_Inlet</entry>
+ </row>
+ <row>
+ <entry>America/Recife</entry>
+ </row>
+ <row>
+ <entry>America/Regina Canada/East-Saskatchewan Canada/Saskatchewan SystemV/CST6</entry>
+ </row>
+ <row>
+ <entry>America/Santiago Chile/Continental</entry>
+ </row>
+ <row>
+ <entry>America/Santo_Domingo</entry>
+ </row>
+ <row>
+ <entry>America/Sao_Paulo Brazil/East</entry>
+ </row>
+ <row>
+ <entry>America/Scoresbysund</entry>
+ </row>
+ <row>
+ <entry>America/St_Johns Canada/Newfoundland</entry>
+ </row>
+ <row>
+ <entry>America/St_Kitts</entry>
+ </row>
+ <row>
+ <entry>America/St_Lucia</entry>
+ </row>
+ <row>
+ <entry>America/St_Thomas America/Virgin</entry>
+ </row>
+ <row>
+ <entry>America/St_Vincent</entry>
+ </row>
+ <row>
+ <entry>America/Swift_Current</entry>
+ </row>
+ <row>
+ <entry>America/Tegucigalpa</entry>
+ </row>
+ <row>
+ <entry>America/Thule</entry>
+ </row>
+ <row>
+ <entry>America/Thunder_Bay</entry>
+ </row>
+ <row>
+ <entry>America/Toronto Canada/Eastern</entry>
+ </row>
+ <row>
+ <entry>America/Tortola</entry>
+ </row>
+ <row>
+ <entry>America/Vancouver Canada/Pacific</entry>
+ </row>
+ <row>
+ <entry>America/Whitehorse Canada/Yukon</entry>
+ </row>
+ <row>
+ <entry>America/Winnipeg Canada/Central</entry>
+ </row>
+ <row>
+ <entry>America/Yakutat</entry>
+ </row>
+ <row>
+ <entry>America/Yellowknife</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Casey</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Davis</entry>
+ </row>
+ <row>
+ <entry>Antarctica/DumontDUrville</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Mawson</entry>
+ </row>
+ <row>
+ <entry>Antarctica/McMurdo Antarctica/South_Pole</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Palmer</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Rothera</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Syowa</entry>
+ </row>
+ <row>
+ <entry>Antarctica/Vostok</entry>
+ </row>
+ <row>
+ <entry>Asia/Aden</entry>
+ </row>
+ <row>
+ <entry>Asia/Almaty</entry>
+ </row>
+ <row>
+ <entry>Asia/Amman</entry>
+ </row>
+ <row>
+ <entry>Asia/Anadyr</entry>
+ </row>
+ <row>
+ <entry>Asia/Aqtau</entry>
+ </row>
+ <row>
+ <entry>Asia/Aqtobe</entry>
+ </row>
+ <row>
+ <entry>Asia/Ashgabat Asia/Ashkhabad</entry>
+ </row>
+ <row>
+ <entry>Asia/Baghdad</entry>
+ </row>
+ <row>
+ <entry>Asia/Bahrain</entry>
+ </row>
+ <row>
+ <entry>Asia/Baku</entry>
+ </row>
+ <row>
+ <entry>Asia/Bangkok</entry>
+ </row>
+ <row>
+ <entry>Asia/Beirut</entry>
+ </row>
+ <row>
+ <entry>Asia/Bishkek</entry>
+ </row>
+ <row>
+ <entry>Asia/Brunei</entry>
+ </row>
+ <row>
+ <entry>Asia/Calcutta</entry>
+ </row>
+ <row>
+ <entry>Asia/Choibalsan</entry>
+ </row>
+ <row>
+ <entry>Asia/Chongqing Asia/Chungking</entry>
+ </row>
+ <row>
+ <entry>Asia/Colombo</entry>
+ </row>
+ <row>
+ <entry>Asia/Dacca Asia/Dhaka</entry>
+ </row>
+ <row>
+ <entry>Asia/Damascus</entry>
+ </row>
+ <row>
+ <entry>Asia/Dili</entry>
+ </row>
+ <row>
+ <entry>Asia/Dubai</entry>
+ </row>
+ <row>
+ <entry>Asia/Dushanbe</entry>
+ </row>
+ <row>
+ <entry>Asia/Gaza</entry>
+ </row>
+ <row>
+ <entry>Asia/Harbin</entry>
+ </row>
+ <row>
+ <entry>Asia/Hong_Kong Hongkong</entry>
+ </row>
+ <row>
+ <entry>Asia/Hovd</entry>
+ </row>
+ <row>
+ <entry>Asia/Irkutsk</entry>
+ </row>
+ <row>
+ <entry>Asia/Jakarta</entry>
+ </row>
+ <row>
+ <entry>Asia/Jayapura</entry>
+ </row>
+ <row>
+ <entry>Asia/Jerusalem Asia/Tel_Aviv Israel</entry>
+ </row>
+ <row>
+ <entry>Asia/Kabul</entry>
+ </row>
+ <row>
+ <entry>Asia/Kamchatka</entry>
+ </row>
+ <row>
+ <entry>Asia/Karachi</entry>
+ </row>
+ <row>
+ <entry>Asia/Kashgar</entry>
+ </row>
+ <row>
+ <entry>Asia/Katmandu</entry>
+ </row>
+ <row>
+ <entry>Asia/Krasnoyarsk</entry>
+ </row>
+ <row>
+ <entry>Asia/Kuala_Lumpur</entry>
+ </row>
+ <row>
+ <entry>Asia/Kuching</entry>
+ </row>
+ <row>
+ <entry>Asia/Kuwait</entry>
+ </row>
+ <row>
+ <entry>Asia/Macao Asia/Macau</entry>
+ </row>
+ <row>
+ <entry>Asia/Magadan</entry>
+ </row>
+ <row>
+ <entry>Asia/Makassar Asia/Ujung_Pandang</entry>
+ </row>
+ <row>
+ <entry>Asia/Manila</entry>
+ </row>
+ <row>
+ <entry>Asia/Muscat</entry>
+ </row>
+ <row>
+ <entry>Asia/Nicosia Europe/Nicosia</entry>
+ </row>
+ <row>
+ <entry>Asia/Novosibirsk</entry>
+ </row>
+ <row>
+ <entry>Asia/Omsk</entry>
+ </row>
+ <row>
+ <entry>Asia/Oral</entry>
+ </row>
+ <row>
+ <entry>Asia/Phnom_Penh</entry>
+ </row>
+ <row>
+ <entry>Asia/Pontianak</entry>
+ </row>
+ <row>
+ <entry>Asia/Pyongyang</entry>
+ </row>
+ <row>
+ <entry>Asia/Qatar</entry>
+ </row>
+ <row>
+ <entry>Asia/Qyzylorda</entry>
+ </row>
+ <row>
+ <entry>Asia/Rangoon</entry>
+ </row>
+ <row>
+ <entry>Asia/Riyadh</entry>
+ </row>
+ <row>
+ <entry>Asia/Riyadh87 Mideast/Riyadh87</entry>
+ </row>
+ <row>
+ <entry>Asia/Riyadh88 Mideast/Riyadh88</entry>
+ </row>
+ <row>
+ <entry>Asia/Riyadh89 Mideast/Riyadh89</entry>
+ </row>
+ <row>
+ <entry>Asia/Saigon</entry>
+ </row>
+ <row>
+ <entry>Asia/Sakhalin</entry>
+ </row>
+ <row>
+ <entry>Asia/Samarkand</entry>
+ </row>
+ <row>
+ <entry>Asia/Seoul ROK</entry>
+ </row>
+ <row>
+ <entry>Asia/Shanghai PRC</entry>
+ </row>
+ <row>
+ <entry>Asia/Singapore Singapore</entry>
+ </row>
+ <row>
+ <entry>Asia/Taipei ROC</entry>
+ </row>
+ <row>
+ <entry>Asia/Tashkent</entry>
+ </row>
+ <row>
+ <entry>Asia/Tbilisi</entry>
+ </row>
+ <row>
+ <entry>Asia/Tehran Iran</entry>
+ </row>
+ <row>
+ <entry>Asia/Thimbu Asia/Thimphu</entry>
+ </row>
+ <row>
+ <entry>Asia/Tokyo Japan</entry>
+ </row>
+ <row>
+ <entry>Asia/Ulaanbaatar Asia/Ulan_Bator</entry>
+ </row>
+ <row>
+ <entry>Asia/Urumqi</entry>
+ </row>
+ <row>
+ <entry>Asia/Vientiane</entry>
+ </row>
+ <row>
+ <entry>Asia/Vladivostok</entry>
+ </row>
+ <row>
+ <entry>Asia/Yakutsk</entry>
+ </row>
+ <row>
+ <entry>Asia/Yekaterinburg</entry>
+ </row>
+ <row>
+ <entry>Asia/Yerevan</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Azores</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Bermuda</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Canary</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Cape_Verde</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Faeroe</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Madeira</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Reykjavik Iceland</entry>
+ </row>
+ <row>
+ <entry>Atlantic/South_Georgia</entry>
+ </row>
+ <row>
+ <entry>Atlantic/St_Helena</entry>
+ </row>
+ <row>
+ <entry>Atlantic/Stanley</entry>
+ </row>
+ <row>
+ <entry>Australia/ACT Australia/Canberra Australia/NSW Australia/Sydney</entry>
+ </row>
+ <row>
+ <entry>Australia/Adelaide Australia/South</entry>
+ </row>
+ <row>
+ <entry>Australia/Brisbane Australia/Queensland</entry>
+ </row>
+ <row>
+ <entry>Australia/Broken_Hill Australia/Yancowinna</entry>
+ </row>
+ <row>
+ <entry>Australia/Darwin Australia/North</entry>
+ </row>
+ <row>
+ <entry>Australia/Hobart Australia/Tasmania</entry>
+ </row>
+ <row>
+ <entry>Australia/LHI Australia/Lord_Howe</entry>
+ </row>
+ <row>
+ <entry>Australia/Lindeman</entry>
+ </row>
+ <row>
+ <entry>Australia/Melbourne Australia/Victoria</entry>
+ </row>
+ <row>
+ <entry>Australia/Perth Australia/West</entry>
+ </row>
+ <row>
+ <entry>CET</entry>
+ </row>
+ <row>
+ <entry>EET</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+1</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+2</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+3</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+4</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+5</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+6</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+7</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+8</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+9</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+10</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+11</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT+12</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-1</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-2</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-3</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-4</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-5</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-6</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-7</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-8</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-9</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-10</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-11</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-12</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-13</entry>
+ </row>
+ <row>
+ <entry>Etc/GMT-14</entry>
+ </row>
+ <row>
+ <entry>Europe/Amsterdam</entry>
+ </row>
+ <row>
+ <entry>Europe/Andorra</entry>
+ </row>
+ <row>
+ <entry>Europe/Athens</entry>
+ </row>
+ <row>
+ <entry>Europe/Belfast</entry>
+ </row>
+ <row>
+ <entry>Europe/Belgrade Europe/Ljubljana Europe/Sarajevo Europe/Skopje Europe/Zagreb</entry>
+ </row>
+ <row>
+ <entry>Europe/Berlin</entry>
+ </row>
+ <row>
+ <entry>Europe/Brussels</entry>
+ </row>
+ <row>
+ <entry>Europe/Bucharest</entry>
+ </row>
+ <row>
+ <entry>Europe/Budapest</entry>
+ </row>
+ <row>
+ <entry>Europe/Chisinau Europe/Tiraspol</entry>
+ </row>
+ <row>
+ <entry>Europe/Copenhagen</entry>
+ </row>
+ <row>
+ <entry>Europe/Dublin Eire</entry>
+ </row>
+ <row>
+ <entry>Europe/Gibraltar</entry>
+ </row>
+ <row>
+ <entry>Europe/Helsinki</entry>
+ </row>
+ <row>
+ <entry>Europe/Istanbul Asia/Istanbul Turkey</entry>
+ </row>
+ <row>
+ <entry>Europe/Kaliningrad</entry>
+ </row>
+ <row>
+ <entry>Europe/Kiev</entry>
+ </row>
+ <row>
+ <entry>Europe/Lisbon Portugal</entry>
+ </row>
+ <row>
+ <entry>Europe/London GB GB-Eire</entry>
+ </row>
+ <row>
+ <entry>Europe/Luxembourg</entry>
+ </row>
+ <row>
+ <entry>Europe/Madrid</entry>
+ </row>
+ <row>
+ <entry>Europe/Malta</entry>
+ </row>
+ <row>
+ <entry>Europe/Minsk</entry>
+ </row>
+ <row>
+ <entry>Europe/Monaco</entry>
+ </row>
+ <row>
+ <entry>Europe/Moscow W-SU</entry>
+ </row>
+ <row>
+ <entry>Europe/Oslo Arctic/Longyearbyen Atlantic/Jan_Mayen</entry>
+ </row>
+ <row>
+ <entry>Europe/Paris</entry>
+ </row>
+ <row>
+ <entry>Europe/Prague Europe/Bratislava</entry>
+ </row>
+ <row>
+ <entry>Europe/Riga</entry>
+ </row>
+ <row>
+ <entry>Europe/Rome Europe/San_Marino Europe/Vatican</entry>
+ </row>
+ <row>
+ <entry>Europe/Samara</entry>
+ </row>
+ <row>
+ <entry>Europe/Simferopol</entry>
+ </row>
+ <row>
+ <entry>Europe/Sofia</entry>
+ </row>
+ <row>
+ <entry>Europe/Stockholm</entry>
+ </row>
+ <row>
+ <entry>Europe/Tallinn</entry>
+ </row>
+ <row>
+ <entry>Europe/Tirane</entry>
+ </row>
+ <row>
+ <entry>Europe/Uzhgorod</entry>
+ </row>
+ <row>
+ <entry>Europe/Vaduz</entry>
+ </row>
+ <row>
+ <entry>Europe/Vienna</entry>
+ </row>
+ <row>
+ <entry>Europe/Vilnius</entry>
+ </row>
+ <row>
+ <entry>Europe/Warsaw Poland</entry>
+ </row>
+ <row>
+ <entry>Europe/Zaporozhye</entry>
+ </row>
+ <row>
+ <entry>Europe/Zurich</entry>
+ </row>
+ <row>
+ <entry>Factory</entry>
+ </row>
+ <row>
+ <entry>GMT GMT+0 GMT-0 GMT0 Greenwich Etc/GMT Etc/GMT+0 Etc/GMT-0 Etc/GMT0 Etc/Greenwich</entry>
+ </row>
+ <row>
+ <entry>Indian/Antananarivo</entry>
+ </row>
+ <row>
+ <entry>Indian/Chagos</entry>
+ </row>
+ <row>
+ <entry>Indian/Christmas</entry>
+ </row>
+ <row>
+ <entry>Indian/Cocos</entry>
+ </row>
+ <row>
+ <entry>Indian/Comoro</entry>
+ </row>
+ <row>
+ <entry>Indian/Kerguelen</entry>
+ </row>
+ <row>
+ <entry>Indian/Mahe</entry>
+ </row>
+ <row>
+ <entry>Indian/Maldives</entry>
+ </row>
+ <row>
+ <entry>Indian/Mauritius</entry>
+ </row>
+ <row>
+ <entry>Indian/Mayotte</entry>
+ </row>
+ <row>
+ <entry>Indian/Reunion</entry>
+ </row>
+ <row>
+ <entry>MET</entry>
+ </row>
+ <row>
+ <entry>Pacific/Apia</entry>
+ </row>
+ <row>
+ <entry>Pacific/Auckland NZ</entry>
+ </row>
+ <row>
+ <entry>Pacific/Chatham NZ-CHAT</entry>
+ </row>
+ <row>
+ <entry>Pacific/Easter Chile/EasterIsland</entry>
+ </row>
+ <row>
+ <entry>Pacific/Efate</entry>
+ </row>
+ <row>
+ <entry>Pacific/Enderbury</entry>
+ </row>
+ <row>
+ <entry>Pacific/Fakaofo</entry>
+ </row>
+ <row>
+ <entry>Pacific/Fiji</entry>
+ </row>
+ <row>
+ <entry>Pacific/Funafuti</entry>
+ </row>
+ <row>
+ <entry>Pacific/Galapagos</entry>
+ </row>
+ <row>
+ <entry>Pacific/Gambier SystemV/YST9</entry>
+ </row>
+ <row>
+ <entry>Pacific/Guadalcanal</entry>
+ </row>
+ <row>
+ <entry>Pacific/Guam</entry>
+ </row>
+ <row>
+ <entry>Pacific/Honolulu HST SystemV/HST10 US/Hawaii</entry>
+ </row>
+ <row>
+ <entry>Pacific/Johnston</entry>
+ </row>
+ <row>
+ <entry>Pacific/Kiritimati</entry>
+ </row>
+ <row>
+ <entry>Pacific/Kosrae</entry>
+ </row>
+ <row>
+ <entry>Pacific/Kwajalein Kwajalein</entry>
+ </row>
+ <row>
+ <entry>Pacific/Majuro</entry>
+ </row>
+ <row>
+ <entry>Pacific/Marquesas</entry>
+ </row>
+ <row>
+ <entry>Pacific/Midway</entry>
+ </row>
+ <row>
+ <entry>Pacific/Nauru</entry>
+ </row>
+ <row>
+ <entry>Pacific/Niue</entry>
+ </row>
+ <row>
+ <entry>Pacific/Norfolk</entry>
+ </row>
+ <row>
+ <entry>Pacific/Noumea</entry>
+ </row>
+ <row>
+ <entry>Pacific/Pago_Pago Pacific/Samoa US/Samoa</entry>
+ </row>
+ <row>
+ <entry>Pacific/Palau</entry>
+ </row>
+ <row>
+ <entry>Pacific/Pitcairn SystemV/PST8</entry>
+ </row>
+ <row>
+ <entry>Pacific/Ponape</entry>
+ </row>
+ <row>
+ <entry>Pacific/Port_Moresby</entry>
+ </row>
+ <row>
+ <entry>Pacific/Rarotonga</entry>
+ </row>
+ <row>
+ <entry>Pacific/Saipan</entry>
+ </row>
+ <row>
+ <entry>Pacific/Tahiti</entry>
+ </row>
+ <row>
+ <entry>Pacific/Tarawa</entry>
+ </row>
+ <row>
+ <entry>Pacific/Tongatapu</entry>
+ </row>
+ <row>
+ <entry>Pacific/Truk</entry>
+ </row>
+ <row>
+ <entry>Pacific/Wake</entry>
+ </row>
+ <row>
+ <entry>Pacific/Wallis</entry>
+ </row>
+ <row>
+ <entry>Pacific/Yap</entry>
+ </row>
+ <row>
+ <entry>UCT Etc/UCT</entry>
+ </row>
+ <row>
+ <entry>UTC Universal Zulu Etc/UTC Etc/Universal Etc/Zulu</entry>
+ </row>
+ <row>
+ <entry>WET</entry>
+ </row>
+</tbody>
+ </tgroup>
+ </table>
+
+ <para>
+ In addition to the names listed in the table,
+ <productname>PostgreSQL</productname> will accept time zone names of the
+ form <replaceable>STD</><replaceable>offset</> or
+ <replaceable>STD</><replaceable>offset</><replaceable>DST</>, where
+ <replaceable>STD</> is a zone abbreviation, <replaceable>offset</> is a
+ numeric offset in hours west from UTC, and <replaceable>DST</> is an
+ optional daylight-savings zone abbreviation, assumed to stand for one hour
+ ahead of the given offset. For example, if <literal>EST5EDT</> were not
+ already a recognized zone name, it would be accepted and would be
+ functionally equivalent to USA East Coast time. When a daylight-savings
+ zone name is present, it is assumed to be used according to USA time zone
+ rules, so this feature is of limited use outside North America.
+ One should also be wary that this provision can lead to
+ silently accepting bogus input, since there is no check on the
+ reasonableness of the zone abbreviations. For example,
+ <literal>SET TIMEZONE TO FOOBAR0</> will work, leaving the system
+ effectively using a rather peculiar abbreviation for GMT.
+ </para>
+
</sect1>
<sect1 id="datetime-units-history">