Timezones overview
Time zones identify the time difference to UTC, the "Universal Time Coordinated." This information is usually written in full hours, sometimes in fractions of hours.In geographically small countries, such as the United Kingdom, with only a small east-to-west extension, often only one time zone is taken. In much broader countries like the US or Russia, time zones sit side by side and there are different times in different parts of the country.
Overview of all current time zones
Americas
Code | Name | Countries/regions | UTC |
---|---|---|---|
ACT | Acre Time | Brazil (Rio Branco) | -5 |
AKST | Alaska Standard TimeIn summer: Alaska Daylight Time (AKDT) | United States of America (Alaska) | -9 |
AMT | Amazon Time | Brazil (Boa Vista, Campo Grande, Manaus, Porto Velho) | -4 |
ART | Argentina Time | Antarctica (Palmer, Rothera), Argentina | -3 |
AST | Atlantic Standard TimeIn summer: Atlantic Daylight Time (ADT) | Anguilla, Antigua and Barbuda, Aruba, Barbados, Bermuda, British Virgin Islands, Canada (Blanc-Sablon, Goose Bay, Moncton), Caribbean Netherlands, Curacao, Dominica, Dominican Republic, Greenland (Thule), Grenada, Guadeloupe, Martinique, Montserrat, Puerto Rico, Saint Barthelemy, Saint Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Maarten, Trinidad and Tobago, Virgin Islands | -4 |
BOT | Bolivia Time | Bolivia | -4 |
BRT | Brasilia Time | Brazil (Bahia, Recife, Sao Paulo) | -3 |
CST | Central Standard TimeIn summer: Central Daylight Time (CDT) | Belize, Canada (Resolute, Winnipeg), Costa Rica, El Salvador, Guatemala, Honduras, Mexico (Chihuahua, Matamoros, Mexico City, Monterrey, Ojinaga), Nicaragua, United States of America (Illinois) | -6 |
CLT | Chile TimeIn summer: Chile Summer Time (CLST) | Chile (Continental) | -4 |
COT | Colombia Time | Colombia | -5 |
CST | Cuba Standard TimeIn summer: Cuba Daylight Time (CDT) | Cuba | -5 |
EST | Eastern Standard TimeIn summer: Eastern Daylight Time (EDT) | Bahamas, Canada (Toronto), Cayman Islands, Haiti, Jamaica, Mexico (Cancun), Panama, Turks and Caicos Islands, United States of America (Michigan, New York) | -5 |
ECT | Ecuador Time | Ecuador (Mainland) | -5 |
FNT | Fernando de Noronha Time | Brazil (Noronha) | -2 |
GFT | French Guiana Time | French Guiana | -3 |
GYT | Guyana Time | Guyana | -4 |
HST | Hawaii Standard TimeIn summer: Hawaii Daylight Time (HDT) | United States of America (Aleutian Islands, Hawaii) | -10 |
MST | Mountain Standard TimeIn summer: Mountain Daylight Time (MDT) | Canada (Cambridge Bay, Dawson, Dawson Creek, Fort Nelson, Inuvik), Mexico (Ciudad Juarez, Hermosillo), United States of America (Colorado, Arizona) | -7 |
NST | Newfoundland Standard TimeIn summer: Newfoundland Daylight Time (NDT) | Canada (St Johns) | -3:30 |
PST | Pacific Standard TimeIn summer: Pacific Daylight Time (PDT) | Canada (Vancouver), Mexico (Tijuana), United States of America (California) | -8 |
PYT | Paraguay TimeIn summer: Paraguay Summer Time (PYST) | Paraguay | -4 |
PET | Peru Time | Peru | -5 |
PMST | Pierre & Miquelon Standard TimeIn summer: Pierre & Miquelon Daylight Time (PMDT) | Saint Pierre and Miquelon | -3 |
SRT | Suriname Time | Suriname | -3 |
UYT | Uruguay Time | Uruguay | -3 |
VET | Venezuelan Standard Time | Venezuela | -4 |
WGT | West Greenland TimeIn summer: West Greenland Summer Time (WGST) | Greenland (Nuuk) | -2 |
Europe
Code | Name | Countries/regions | UTC |
---|---|---|---|
CET | Central European TimeIn summer: Central European Summertime (CEST) | Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Bouvet Island, Croatia, Czechia, Denmark, France, Germany, Gibraltar, Hungary, Italy, Kosovo, Liechtenstein, Luxembourg, Malta, Montenegro, Netherlands, North Macedonia, Norway, Poland, Principality of Monaco, San Marino, Serbia, Slovakia, Slovenia, Spain (Ceuta, Mainland), Svalbard, Sweden, Switzerland, Vatican City | +1 |
EET | Eastern European TimeIn summer: Eastern European Summertime (EEST) | Bulgaria, Cyprus, Egypt, Estonia, Finland, Greece, Latvia, Lebanon, Libya, Lithuania, Moldova, Palestine, Romania, Russia (Kaliningrad), Ukraine (Mainland), Åland Islands | +2 |
MSK | Moscow Standard Time | Belarus, Russia (Moscow, Volgograd), Ukraine (Crimean Peninsula) | +3 |
SAMT | Samara Time | Russia (Samara) | +4 |
TRT | Turkey Time | Turkey | +3 |
WET | Western European TimeIn summer: Western European Summertime (WEST) | Faroe Islands, Portugal (Madeira, Lisbon), Spain (Canary Islands) | +0 |
Africa
Code | Name | Countries/regions | UTC |
---|---|---|---|
CAT | Central Africa Time | Botswana, Burundi, Democratic Republic of the Congo (Lubumbashi), Malawi, Mozambique, Namibia, Rwanda, South Sudan, Sudan, Zambia, Zimbabwe | +2 |
EAT | Eastern Africa Time | Comoros, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Mayotte, Somalia, Tanzania, Uganda | +3 |
GMT | Greenwich Mean Time | Antarctica (Troll), Burkina Faso, Gambia, Ghana, Greenland (Danmarkshavn), Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Saint Helena, Ascension and Tristan da Cunha, Sao Tome and Principe, Senegal, Sierra Leone, Togo, United Kingdom | +0 |
SAST | South Africa Standard Time | Eswatini, Lesotho, South Africa | +2 |
WAT | West Africa Time | Algeria, Angola, Benin, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo (Kinshasa), Equatorial Guinea, Gabon, Morocco, Niger, Nigeria, Republic of the Congo, Tunisia, Western Sahara | +1 |
Asia
Code | Name | Countries/regions | UTC |
---|---|---|---|
AFT | Afghanistan Time | Afghanistan | +4:30 |
ALMT | Alma-Ata Time | Kazakhstan (Almaty) | +5 |
ANAT | Anadyr Time | Russia (Anadyr) | +12 |
AQTT | Aqtobe Time | Kazakhstan (Aqtobe, Qostanay) | +5 |
AST | Arabia Standard Time | Bahrain, Iraq, Jordan, Kuwait, Qatar, Saudi Arabia, Syria, Yemen | +3 |
AMT | Armenia Time | Armenia | +4 |
AZT | Azerbaijan Time | Azerbaijan | +4 |
BST | Bangladesh Standard Time | Bangladesh | +6 |
BTT | Bhutan Time | Bhutan | +6 |
BNT | Brunei Darussalam Time | Brunei | +8 |
CIT | Central Indonesia Time | Indonesia (Sulawesi) | +8 |
CST | China Standard Time | China (Shanghai), Macao, Taiwan | +8 |
CHOT | Choibalsan Time | Mongolia (Choibalsan) | +8 |
TLT | East Timor Time | East Timor | +9 |
EIT | Eastern Indonesia Time | Indonesia (Papua) | +9 |
GET | Georgia Time | Georgia | +4 |
GST | Gulf Standard Time | Oman, United Arab Emirates | +4 |
HKT | Hong Kong Time | Hong Kong | +8 |
HOVT | Hovd Time | Mongolia (Hovd) | +7 |
IST | India Standard Time | India | +5:30 |
ICT | Indochina Time | Cambodia, Laos, Thailand, Vietnam | +7 |
IRST | Iran Standard Time | Iran | +3:30 |
IRKT | Irkutsk Time | Russia (Irkutsk) | +8 |
IST | Israel Standard TimeIn summer: Israel Daylight Time (IDT) | Israel | +2 |
JST | Japan Standard Time | Japan | +9 |
PETT | Kamchatka Time | Russia (Kamchatka) | +12 |
KST | Korea Standard Time | North Korea, South Korea | +9 |
KRAT | Krasnoyarsk Time | Russia (Krasnoyarsk) | +7 |
KGT | Kyrgyzstan Time | Kyrgyzstan | +6 |
MYT | Malaysia Time | Malaysia | +8 |
MMT | Myanmar Time | Myanmar | +6:30 |
NPT | Nepal Time | Nepal | +5:45 |
NOVT | Novosibirsk Time | Russia (Novosibirsk) | +7 |
OMST | Omsk Standard Time | Russia (Omsk) | +6 |
ORAT | Oral Time | Kazakhstan (Oral) | +5 |
PKT | Pakistan Standard Time | Pakistan | +5 |
PHT | Philippine Time | Philippines | +8 |
QYZT | Qyzylorda Time | Kazakhstan (Qyzylorda) | +5 |
SAKT | Sakhalin Time | Russia (Sakhalin) | +11 |
SGT | Singapore Time | Singapore | +8 |
SRET | Srednekolymsk Time | Russia (Srednekolymsk) | +11 |
SLT | Sri Lanka Time | Sri Lanka | +5:30 |
TJT | Tajikistan Time | Tajikistan | +5 |
TMT | Turkmenistan Time | Turkmenistan | +5 |
ULAT | Ulaanbaatar Time | Mongolia (Ulaanbaatar) | +8 |
UZT | Uzbekistan Time | Uzbekistan | +5 |
VLAT | Vladivostok Time | Russia (Vladivostok) | +10 |
WIT | Western Indonesia Time | Indonesia (Sumatra, Java) | +7 |
XJT | Xinjiang Time | China (Urumqi) | +6 |
YAKT | Yakutsk Time | Russia (Yakutsk) | +9 |
YEKT | Yekaterinburg Time | Russia (Yekaterinburg) | +5 |
Australia
Code | Name | Countries/regions | UTC |
---|---|---|---|
ACST | Australian Central TimeIn summer: Australian Central Daylight Time (ACDT) | Australia (South Australia, Broken Hill, Northern Territory) | +9:30 |
ACWST | Australian Central Western Standard Time | Australia (Eucla) | +8:45 |
AEST | Australian Eastern Standard TimeIn summer: Australian Eastern Daylight Time (AEDT) | Antarctica (Macquarie), Australia (Queensland, Victoria, New South Wales) | +10 |
AWST | Australian Western Standard Time | Australia (Western Australia) | +8 |
LHST | Lord Howe Standard TimeIn summer: Lord Howe Daylight Time (LHDT) | Australia (Lord Howe Island) | +10:30 |
Indian Ocean
Code | Name | Countries/regions | UTC |
---|---|---|---|
CXT | Christmas Island Time | Christmas Island | +7 |
CCT | Cocos Islands Time | Cocos (Keeling) Islands | +6:30 |
TFT | French Southern and Antarctic Time | French Southern and Antarctic Lands, Heard Island and McDonald Islands | +5 |
ICT | Indian Chagos Time | British Indian Ocean Territory | +6 |
MVT | Maldives Time | Maldives | +5 |
MUT | Mauritius Time | Mauritius | +4 |
RET | Reunion Time | Reunion | +4 |
SCT | Seychelles Time | Seychelles | +4 |
Pacific Ocean
Code | Name | Countries/regions | UTC |
---|---|---|---|
CHST | Chamorro Standard Time | Guam, Northern Mariana Islands | +10 |
CHAST | Chatham Island Standard TimeIn summer: Chatham Island Daylight Time (CHADT) | New Zealand (Chatham) | +12:45 |
CHUT | Chuuk Time | Federated States of Micronesia (Chuuk) | +10 |
CKT | Cook Island Time | Cook Islands | -10 |
EAST | Easter Island Standard TimeIn summer: Easter Island Summer Time (EASST) | Chile (Easter Islands) | -6 |
FJT | Fiji Time | Fiji | +12 |
GALT | Galapagos Time | Ecuador (Galapagos Islands) | -6 |
GAMT | Gambier Time | French Polynesia (Gambier) | -9 |
GILT | Gilbert Island Time | Kiribati (Tarawa) | +12 |
KOST | Kosrae Time | Federated States of Micronesia (Kosrae) | +11 |
LINT | Line Islands Time | Kiribati (Kiritimati) | +14 |
MART | Marquesas Time | French Polynesia (Marquesas) | -9:30 |
MHT | Marshall Islands Time | Marshall Islands | +12 |
NRT | Nauru Time | Nauru | +12 |
NCT | New Caledonia Time | New Caledonia | +11 |
NZST | New Zealand Standard TimeIn summer: New Zealand Daylight Time (NZDT) | Antarctica (McMurdo), New Zealand (Auckland) | +12 |
NUT | Niue Time | Niue | -11 |
NFT | Norfolk TimeIn summer: Norfolk Daylight Time (NFDT) | Norfolk Island | +11 |
PWT | Palau Time | Palau | +9 |
PGT | Papua New Guinea Time | Papua New Guinea | +10 |
PHOT | Phoenix Island Time | Kiribati (Kanton) | +13 |
PST | Pitcairn Standard Time | Pitcairn Islands | -8 |
PONT | Pohnpei Standard Time | Federated States of Micronesia (Pohnpei) | +11 |
SST | Samoa Standard Time | American Samoa, United States Minor Outlying Islands (Midway) | -11 |
SBT | Solomon Islands Time | Solomon Islands | +11 |
TAHT | Tahiti Time | French Polynesia (Tahiti) | -10 |
TKT | Tokelau Time | Tokelau | +13 |
TOT | Tonga Time | Tonga | +13 |
TVT | Tuvalu Time | Tuvalu | +12 |
VUT | Vanuatu Time | Vanuatu | +11 |
WAKT | Wake Island Time | United States Minor Outlying Islands (Wake) | +12 |
WFT | Wallis and Futuna Time | Wallis and Futuna | +12 |
WST | West Samoa Time | Samoa | +13 |
Atlantic Ocean
Code | Name | Countries/regions | UTC |
---|---|---|---|
AZOT | Azores TimeIn summer: Azores Summer Time (AZOST) | Portugal (Azores) | -1 |
CVT | Cape Verde Time | Cape Verde | -1 |
FKT | Falkland Islands Time | Falkland Islands | -3 |
GST | South Georgia Time | South Georgia and South Sandwich Islands | -2 |
Antarctica
Code | Name | Countries/regions | UTC |
---|---|---|---|
CAST | Casey Time | Antarctica (Casey) | +8 |
DAVT | Davis Time | Antarctica (Davis) | +7 |
DDUT | Dumont-d'Urville Time | Antarctica (DumontDUrville) | +10 |
MAWT | Mawson Time | Antarctica (Mawson) | +5 |
SYOT | Syowa Time | Antarctica (Syowa) | +3 |
VOST | Vostok Time | Antarctica (Vostok) | +5 |
Inconsistent and duplicate abbreviations
The abbreviations of the individual zones, such as "CST" or "CET", are often confusing. In fact, they are the result of regular use rather than standardization. The ISO 8601 standard specifies spellings and components of the international format, but these abbreviations do not appear there.In fact, the abbreviations often used today are anything but clear or understandable. The abbreviation "AST" stands for both, the American Atlantic Standard Time and Arabia Standard Time. Other abbreviations such as AMT, CST, GFT, GST, ICT, IST and PST are also used more than once. The current use of these abbreviations therefore only makes sense if it is clear from the context which geographical region is being referred to. The term CST is widely used within the USA and makes sense in most cases, because using the clunky term "Central Standard Time" would be too cumbersome in the vast majority of cases anyway. However, it must be clear that it is not China Standard Time (13 hours ahead of Central Standard Time) or Cuba Standard Time (1 hour ahead).
The letter "S" often causes confusion. In Europe, the terms summer time and winter time have become established. Winter time is the standard time. As a result, some time zones refer to themselves as "summer time", others as "standard time". Both can be found with an "S" in the abbreviation. The abbreviation UYST, for example, stands for Uruguay Summer Time, but not for Uruguay Standard Time. In many other countries, summer time is called "daylight time" and is abbreviated with a "D". In many cases, the "S" or "D" is added to the 3-letter abbreviation of standard time (CET, CEST). However, even this spelling is not standardized. In other zones, the letters are simply exchanged (AST, ADT).
The abandonment of daylight saving time in many countries leads to a further complication. Time zones that no longer have daylight saving time sometimes sometimes dispense with the suffix "Standard". For example, Singapore Standard Time (SST) has now become Singapore Time (SGT). The first two letters were taken from the international 2-letter country abbreviation.
Time zone allocation
Since a day has 24 hours, the globe was divided into 24 equal theoretical parts, each extending from the North Pole to the South Pole. Each of these sections is 15 degrees of longitude wide and marks one hour. The zero longitude is the UTC0 zone time, while the 15th longitude is the UTC+1 time. Thus, in each of these optimized sections, the time is aligned optimally to the position of the sun, based on where the sun is highest at noon everywhereOf course, this purely theoretical structure cannot be combined with national borders. The western parts of Mexico are actually in the UTC-7 time zone, but UTC-6 applies to the whole country. Numerous countries therefore opt for a uniform time zone within its own borders. For example, there is Spain (actually in the UTC0 time zone), which orients to its neighbours and accepts other time zones for political and economic reasons rather than using the position of the sun.
This cannot be achieved in large countries, either. In Brazil, for example, there are three different time zones within the country, while there are six in the USA and Russia has eleven. Australia has five time zones, which, depending on the part of the country, are not even separated hourly and do not all have a daylight saving time.
The big outlier is China. Although the country extends over five theoretical time zones, for political reasons, the time zone for Beijing, the capital, has been decreed for the whole country. Thus there is a large time difference at China’s western border to Pakistan and Tajikistan: On the other side of the border, one must change the time a full three hours. For the sake of completeness: Only the autonomous region Xinjiang in the extreme west of China has its own time zone.
The Date Line
The date line runs at the 180th longitude and thus in the middle of the Pacific Ocean. If one crosses this border from west to east, one has to deduct a whole day. From east to west (thus in direction to Asia), one adds one day. This position is not by coincidence. Since a date change has to take place at some point during the 24-hour division, the most remote and sparsely populated place on earth, which lies between America and Asia, was used intentionally for this purpose. From this the position, we get the exact other side of the globe and draw a vertical line, the zero meridian in Greenwich — a suburb of London. Until 1884, completely different coordinate systems were used depending on the country, which also had a date line, but originated in their own country.Occasionally, individual countries switch from one side of the dateline to the other for political reasons. For example, in 1995, Kiribati placed its former two-day territory in the UTC+12 time zone. Samoa also moved back to the West in 2011 because trade relations with the eastern regions played an increasingly minor role.