Timezone

From Leo's Notes
Last edited on 7 September 2022, at 04:27.

On Linux, the timezone is typically set using the /etc/localtime file. This file is typically a symlink to an actual binary tzfile in /usr/share/zoneinfo/ named after the timezone identifier such as "America/Edmonton".

A tzfile contains the timezone information used by the tzset function as part of libc. The file format is described in tzfile(5).

The timezone database is maintained by IANA and the latest version can be obtained from http://www.iana.org/time-zones.

TZ Environment Variable

Systems with no timezone database files (such as embedded systems) will typically have the timezone set using the TZ environment variable. Embedded systems will typically read and export the TZ variable from a file such as /etc/TZ.

This method can also be used to override the system timezone for an individual program by specifying it in its environment. For example, TZ=HKT-8 date or TZ='Asia/Hong_Kong' date.

If using the TZ variable, refer to the following table for the proper values. Alternatively, you may also run the 'tzselect' command for help identifying the appropriate TZ value.

Location TZ string
Africa/Abidjan GMT0
Africa/Accra GMT0
Africa/Addis Ababa EAT-3
Africa/Algiers CET-1
Africa/Asmara EAT-3
Africa/Bamako GMT0
Africa/Bangui WAT-1
Africa/Banjul GMT0
Africa/Bissau GMT0
Africa/Blantyre CAT-2
Africa/Brazzaville WAT-1
Africa/Bujumbura CAT-2
Africa/Casablanca WET0
Africa/Ceuta CET-1CEST,M3.5.0,M10.5.0/3
Africa/Conakry GMT0
Africa/Dakar GMT0
Africa/Dar es Salaam EAT-3
Africa/Djibouti EAT-3
Africa/Douala WAT-1
Africa/El Aaiun WET0
Africa/Freetown GMT0
Africa/Gaborone CAT-2
Africa/Harare CAT-2
Africa/Johannesburg SAST-2
Africa/Kampala EAT-3
Africa/Khartoum EAT-3
Africa/Kigali CAT-2
Africa/Kinshasa WAT-1
Africa/Lagos WAT-1
Africa/Libreville WAT-1
Africa/Lome GMT0
Africa/Luanda WAT-1
Africa/Lubumbashi CAT-2
Africa/Lusaka CAT-2
Africa/Malabo WAT-1
Africa/Maputo CAT-2
Africa/Maseru SAST-2
Africa/Mbabane SAST-2
Africa/Mogadishu EAT-3
Africa/Monrovia GMT0
Africa/Nairobi EAT-3
Africa/Ndjamena WAT-1
Africa/Niamey WAT-1
Africa/Nouakchott GMT0
Africa/Ouagadougou GMT0
Africa/Porto-Novo WAT-1
Africa/Sao Tome GMT0
Africa/Tripoli EET-2
Africa/Tunis CET-1
Africa/Windhoek WAT-1WAST,M9.1.0,M4.1.0
America/Adak HAST10HADT,M3.2.0,M11.1.0
America/Anchorage AKST9AKDT,M3.2.0,M11.1.0
America/Anguilla AST4
America/Antigua AST4
America/Araguaina BRT3
America/Argentina/Buenos Aires ART3
America/Argentina/Catamarca ART3
America/Argentina/Cordoba ART3
America/Argentina/Jujuy ART3
America/Argentina/La Rioja ART3
America/Argentina/Mendoza ART3
America/Argentina/Rio Gallegos ART3
America/Argentina/Salta ART3
America/Argentina/San Juan ART3
America/Argentina/Tucuman ART3
America/Argentina/Ushuaia ART3
America/Aruba AST4
America/Asuncion PYT4PYST,M10.1.0/0,M4.2.0/0
America/Atikokan EST5
America/Bahia BRT3
America/Barbados AST4
America/Belem BRT3
America/Belize CST6
America/Blanc-Sablon AST4
America/Boa Vista AMT4
America/Bogota COT5
America/Boise MST7MDT,M3.2.0,M11.1.0
America/Cambridge Bay MST7MDT,M3.2.0,M11.1.0
America/Campo Grande AMT4AMST,M10.3.0/0,M2.3.0/0
America/Cancun CST6CDT,M4.1.0,M10.5.0
America/Caracas VET4:30
America/Cayenne GFT3
America/Cayman EST5
America/Chicago CST6CDT,M3.2.0,M11.1.0
America/Chihuahua MST7MDT,M4.1.0,M10.5.0
America/Costa Rica CST6
America/Cuiaba AMT4AMST,M10.3.0/0,M2.3.0/0
America/Curacao AST4
America/Danmarkshavn GMT0
America/Dawson PST8PDT,M3.2.0,M11.1.0
America/Dawson Creek MST7
America/Denver MST7MDT,M3.2.0,M11.1.0
America/Detroit EST5EDT,M3.2.0,M11.1.0
America/Dominica AST4
America/Edmonton MST7MDT,M3.2.0,M11.1.0
America/Eirunepe AMT4
America/El Salvador CST6
America/Fortaleza BRT3
America/Glace Bay AST4ADT,M3.2.0,M11.1.0
America/Goose Bay AST4ADT,M3.2.0/0:01,M11.1.0/0:01
America/Grand Turk EST5EDT,M3.2.0,M11.1.0
America/Grenada AST4
America/Guadeloupe AST4
America/Guatemala CST6
America/Guayaquil ECT5
America/Guyana GYT4
America/Halifax AST4ADT,M3.2.0,M11.1.0
America/Havana CST5CDT,M3.2.0/0,M10.5.0/1
America/Hermosillo MST7
America/Indiana/Indianapolis EST5EDT,M3.2.0,M11.1.0
America/Indiana/Knox CST6CDT,M3.2.0,M11.1.0
America/Indiana/Marengo EST5EDT,M3.2.0,M11.1.0
America/Indiana/Petersburg EST5EDT,M3.2.0,M11.1.0
America/Indiana/Tell City CST6CDT,M3.2.0,M11.1.0
America/Indiana/Vevay EST5EDT,M3.2.0,M11.1.0
America/Indiana/Vincennes EST5EDT,M3.2.0,M11.1.0
America/Indiana/Winamac EST5EDT,M3.2.0,M11.1.0
America/Inuvik MST7MDT,M3.2.0,M11.1.0
America/Iqaluit EST5EDT,M3.2.0,M11.1.0
America/Jamaica EST5
America/Juneau AKST9AKDT,M3.2.0,M11.1.0
America/Kentucky/Louisville EST5EDT,M3.2.0,M11.1.0
America/Kentucky/Monticello EST5EDT,M3.2.0,M11.1.0
America/La Paz BOT4
America/Lima PET5
America/Los Angeles PST8PDT,M3.2.0,M11.1.0
America/Maceio BRT3
America/Managua CST6
America/Manaus AMT4
America/Marigot AST4
America/Martinique AST4
America/Matamoros CST6CDT,M3.2.0,M11.1.0
America/Mazatlan MST7MDT,M4.1.0,M10.5.0
America/Menominee CST6CDT,M3.2.0,M11.1.0
America/Merida CST6CDT,M4.1.0,M10.5.0
America/Mexico City CST6CDT,M4.1.0,M10.5.0
America/Miquelon PMST3PMDT,M3.2.0,M11.1.0
America/Moncton AST4ADT,M3.2.0,M11.1.0
America/Monterrey CST6CDT,M4.1.0,M10.5.0
America/Montevideo UYT3UYST,M10.1.0,M3.2.0
America/Montreal EST5EDT,M3.2.0,M11.1.0
America/Montserrat AST4
America/Nassau EST5EDT,M3.2.0,M11.1.0
America/New York EST5EDT,M3.2.0,M11.1.0
America/Nipigon EST5EDT,M3.2.0,M11.1.0
America/Nome AKST9AKDT,M3.2.0,M11.1.0
America/Noronha FNT2
America/North Dakota/Center CST6CDT,M3.2.0,M11.1.0
America/North Dakota/New Salem CST6CDT,M3.2.0,M11.1.0
America/Ojinaga MST7MDT,M3.2.0,M11.1.0
America/Panama EST5
America/Pangnirtung EST5EDT,M3.2.0,M11.1.0
America/Paramaribo SRT3
America/Phoenix MST7
America/Port of Spain AST4
America/Port-au-Prince EST5
America/Porto Velho AMT4
America/Puerto Rico AST4
America/Rainy River CST6CDT,M3.2.0,M11.1.0
America/Rankin Inlet CST6CDT,M3.2.0,M11.1.0
America/Recife BRT3
America/Regina CST6
America/Rio Branco AMT4
America/Santa Isabel PST8PDT,M4.1.0,M10.5.0
America/Santarem BRT3
America/Santo Domingo AST4
America/Sao Paulo BRT3BRST,M10.3.0/0,M2.3.0/0
America/Scoresbysund EGT1EGST,M3.5.0/0,M10.5.0/1
America/Shiprock MST7MDT,M3.2.0,M11.1.0
America/St Barthelemy AST4
America/St Johns NST3:30NDT,M3.2.0/0:01,M11.1.0/0:01
America/St Kitts AST4
America/St Lucia AST4
America/St Thomas AST4
America/St Vincent AST4
America/Swift Current CST6
America/Tegucigalpa CST6
America/Thule AST4ADT,M3.2.0,M11.1.0
America/Thunder Bay EST5EDT,M3.2.0,M11.1.0
America/Tijuana PST8PDT,M3.2.0,M11.1.0
America/Toronto EST5EDT,M3.2.0,M11.1.0
America/Tortola AST4
America/Vancouver PST8PDT,M3.2.0,M11.1.0
America/Whitehorse PST8PDT,M3.2.0,M11.1.0
America/Winnipeg CST6CDT,M3.2.0,M11.1.0
America/Yakutat AKST9AKDT,M3.2.0,M11.1.0
America/Yellowknife MST7MDT,M3.2.0,M11.1.0
Antarctica/Casey WST-8
Antarctica/Davis DAVT-7
Antarctica/DumontDUrville DDUT-10
Antarctica/Macquarie MIST-11
Antarctica/Mawson MAWT-5
Antarctica/McMurdo NZST-12NZDT,M9.5.0,M4.1.0/3
Antarctica/Rothera ROTT3
Antarctica/South Pole NZST-12NZDT,M9.5.0,M4.1.0/3
Antarctica/Syowa SYOT-3
Antarctica/Vostok VOST-6
Arctic/Longyearbyen CET-1CEST,M3.5.0,M10.5.0/3
Asia/Aden AST-3
Asia/Almaty ALMT-6
Asia/Anadyr ANAT-11ANAST,M3.5.0,M10.5.0/3
Asia/Aqtau AQTT-5
Asia/Aqtobe AQTT-5
Asia/Ashgabat TMT-5
Asia/Baghdad AST-3
Asia/Bahrain AST-3
Asia/Baku AZT-4AZST,M3.5.0/4,M10.5.0/5
Asia/Bangkok ICT-7
Asia/Beirut EET-2EEST,M3.5.0/0,M10.5.0/0
Asia/Bishkek KGT-6
Asia/Brunei BNT-8
Asia/Choibalsan CHOT-8
Asia/Chongqing CST-8
Asia/Colombo IST-5:30
Asia/Damascus EET-2EEST,M4.1.5/0,M10.5.5/0
Asia/Dhaka BDT-6
Asia/Dili TLT-9
Asia/Dubai GST-4
Asia/Dushanbe TJT-5
Asia/Gaza EET-2EEST,M3.5.6/0:01,M9.1.5
Asia/Harbin CST-8
Asia/Ho Chi Minh ICT-7
Asia/Hong Kong HKT-8
Asia/Hovd HOVT-7
Asia/Irkutsk IRKT-8IRKST,M3.5.0,M10.5.0/3
Asia/Jakarta WIT-7
Asia/Jayapura EIT-9
Asia/Kabul AFT-4:30
Asia/Kamchatka PETT-11PETST,M3.5.0,M10.5.0/3
Asia/Karachi PKT-5
Asia/Kashgar CST-8
Asia/Kathmandu NPT-5:45
Asia/Kolkata IST-5:30
Asia/Krasnoyarsk KRAT-7KRAST,M3.5.0,M10.5.0/3
Asia/Kuala Lumpur MYT-8
Asia/Kuching MYT-8
Asia/Kuwait AST-3
Asia/Macau CST-8
Asia/Magadan MAGT-11MAGST,M3.5.0,M10.5.0/3
Asia/Makassar CIT-8
Asia/Manila PHT-8
Asia/Muscat GST-4
Asia/Nicosia EET-2EEST,M3.5.0/3,M10.5.0/4
Asia/Novokuznetsk NOVT-6NOVST,M3.5.0,M10.5.0/3
Asia/Novosibirsk NOVT-6NOVST,M3.5.0,M10.5.0/3
Asia/Omsk OMST-7
Asia/Oral ORAT-5
Asia/Phnom Penh ICT-7
Asia/Pontianak WIT-7
Asia/Pyongyang KST-9
Asia/Qatar AST-3
Asia/Qyzylorda QYZT-6
Asia/Rangoon MMT-6:30
Asia/Riyadh AST-3
Asia/Sakhalin SAKT-10SAKST,M3.5.0,M10.5.0/3
Asia/Samarkand UZT-5
Asia/Seoul KST-9
Asia/Shanghai CST-8
Asia/Singapore SGT-8
Asia/Taipei CST-8
Asia/Tashkent UZT-5
Asia/Tbilisi GET-4
Asia/Tehran IRST-3:30IRDT,80/0,264/0
Asia/Thimphu BTT-6
Asia/Tokyo JST-9
Asia/Ulaanbaatar ULAT-8
Asia/Urumqi CST-8
Asia/Vientiane ICT-7
Asia/Vladivostok VLAT-10VLAST,M3.5.0,M10.5.0/3
Asia/Yakutsk YAKT-9YAKST,M3.5.0,M10.5.0/3
Asia/Yekaterinburg YEKT-5YEKST,M3.5.0,M10.5.0/3
Asia/Yerevan AMT-4AMST,M3.5.0,M10.5.0/3
Atlantic/Azores AZOT1AZOST,M3.5.0/0,M10.5.0/1
Atlantic/Bermuda AST4ADT,M3.2.0,M11.1.0
Atlantic/Canary WET0WEST,M3.5.0/1,M10.5.0
Atlantic/Cape Verde CVT1
Atlantic/Faroe WET0WEST,M3.5.0/1,M10.5.0
Atlantic/Madeira WET0WEST,M3.5.0/1,M10.5.0
Atlantic/Reykjavik GMT0
Atlantic/South Georgia GST2
Atlantic/St Helena GMT0
Atlantic/Stanley FKT4FKST,M9.1.0,M4.3.0
Australia/Adelaide CST-9:30CST,M10.1.0,M4.1.0/3
Australia/Brisbane EST-10
Australia/Broken Hill CST-9:30CST,M10.1.0,M4.1.0/3
Australia/Currie EST-10EST,M10.1.0,M4.1.0/3
Australia/Darwin CST-9:30
Australia/Eucla CWST-8:45
Australia/Hobart EST-10EST,M10.1.0,M4.1.0/3
Australia/Lindeman EST-10
Australia/Lord Howe LHST-10:30LHST-11,M10.1.0,M4.1.0
Australia/Melbourne EST-10EST,M10.1.0,M4.1.0/3
Australia/Perth WST-8
Australia/Sydney EST-10EST,M10.1.0,M4.1.0/3
Europe/Amsterdam CET-1CEST,M3.5.0,M10.5.0/3
Europe/Andorra CET-1CEST,M3.5.0,M10.5.0/3
Europe/Athens EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Belgrade CET-1CEST,M3.5.0,M10.5.0/3
Europe/Berlin CET-1CEST,M3.5.0,M10.5.0/3
Europe/Bratislava CET-1CEST,M3.5.0,M10.5.0/3
Europe/Brussels CET-1CEST,M3.5.0,M10.5.0/3
Europe/Bucharest EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Budapest CET-1CEST,M3.5.0,M10.5.0/3
Europe/Chisinau EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Copenhagen CET-1CEST,M3.5.0,M10.5.0/3
Europe/Dublin GMT0IST,M3.5.0/1,M10.5.0
Europe/Gibraltar CET-1CEST,M3.5.0,M10.5.0/3
Europe/Guernsey GMT0BST,M3.5.0/1,M10.5.0
Europe/Helsinki EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Isle of Man GMT0BST,M3.5.0/1,M10.5.0
Europe/Istanbul EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Jersey GMT0BST,M3.5.0/1,M10.5.0
Europe/Kaliningrad EET-2EEST,M3.5.0,M10.5.0/3
Europe/Kiev EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Lisbon WET0WEST,M3.5.0/1,M10.5.0
Europe/Ljubljana CET-1CEST,M3.5.0,M10.5.0/3
Europe/London GMT0BST,M3.5.0/1,M10.5.0
Europe/Luxembourg CET-1CEST,M3.5.0,M10.5.0/3
Europe/Madrid CET-1CEST,M3.5.0,M10.5.0/3
Europe/Malta CET-1CEST,M3.5.0,M10.5.0/3
Europe/Mariehamn EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Minsk EET-2EEST,M3.5.0,M10.5.0/3
Europe/Monaco CET-1CEST,M3.5.0,M10.5.0/3
Europe/Moscow MSK-4
Europe/Oslo CET-1CEST,M3.5.0,M10.5.0/3
Europe/Paris CET-1CEST,M3.5.0,M10.5.0/3
Europe/Podgorica CET-1CEST,M3.5.0,M10.5.0/3
Europe/Prague CET-1CEST,M3.5.0,M10.5.0/3
Europe/Riga EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Rome CET-1CEST,M3.5.0,M10.5.0/3
Europe/Samara SAMT-3SAMST,M3.5.0,M10.5.0/3
Europe/San Marino CET-1CEST,M3.5.0,M10.5.0/3
Europe/Sarajevo CET-1CEST,M3.5.0,M10.5.0/3
Europe/Simferopol EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Skopje CET-1CEST,M3.5.0,M10.5.0/3
Europe/Sofia EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Stockholm CET-1CEST,M3.5.0,M10.5.0/3
Europe/Tallinn EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Tirane CET-1CEST,M3.5.0,M10.5.0/3
Europe/Uzhgorod EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Vaduz CET-1CEST,M3.5.0,M10.5.0/3
Europe/Vatican CET-1CEST,M3.5.0,M10.5.0/3
Europe/Vienna CET-1CEST,M3.5.0,M10.5.0/3
Europe/Vilnius EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Volgograd VOLT-3VOLST,M3.5.0,M10.5.0/3
Europe/Warsaw CET-1CEST,M3.5.0,M10.5.0/3
Europe/Zagreb CET-1CEST,M3.5.0,M10.5.0/3
Europe/Zaporozhye EET-2EEST,M3.5.0/3,M10.5.0/4
Europe/Zurich CET-1CEST,M3.5.0,M10.5.0/3
Indian/Antananarivo EAT-3
Indian/Chagos IOT-6
Indian/Christmas CXT-7
Indian/Cocos CCT-6:30
Indian/Comoro EAT-3
Indian/Kerguelen TFT-5
Indian/Mahe SCT-4
Indian/Maldives MVT-5
Indian/Mauritius MUT-4
Indian/Mayotte EAT-3
Indian/Reunion RET-4
Pacific/Apia WST11
Pacific/Auckland NZST-12NZDT,M9.5.0,M4.1.0/3
Pacific/Chatham CHAST-12:45CHADT,M9.5.0/2:45,M4.1.0/3:45
Pacific/Efate VUT-11
Pacific/Enderbury PHOT-13
Pacific/Fakaofo TKT10
Pacific/Fiji FJT-12
Pacific/Funafuti TVT-12
Pacific/Galapagos GALT6
Pacific/Gambier GAMT9
Pacific/Guadalcanal SBT-11
Pacific/Guam ChST-10
Pacific/Honolulu HST10
Pacific/Johnston HST10
Pacific/Kiritimati LINT-14
Pacific/Kosrae KOST-11
Pacific/Kwajalein MHT-12
Pacific/Majuro MHT-12
Pacific/Marquesas MART9:30
Pacific/Midway SST11
Pacific/Nauru NRT-12
Pacific/Niue NUT11
Pacific/Norfolk NFT-11:30
Pacific/Noumea NCT-11
Pacific/Pago Pago SST11
Pacific/Palau PWT-9
Pacific/Pitcairn PST8
Pacific/Ponape PONT-11
Pacific/Port Moresby PGT-10
Pacific/Rarotonga CKT10
Pacific/Saipan ChST-10
Pacific/Tahiti TAHT10
Pacific/Tarawa GILT-12
Pacific/Tongatapu TOT-13
Pacific/Truk TRUT-10
Pacific/Wake WAKT-12
Pacific/Wallis WFT-12

See Also