This is a list of countries, regions, and territories grouped by '''time zone'''.

Although many time zones have descriptive names used by people in them, they are least ambiguously identified by their relationship to '''UTC''' (Universal Time, Co-ordinated). UTC used to be called '''GMT''' (Greenwich Mean Time), after the Royal Observatory located in the Greenwich area of London.

UTC is also sometimes called '''Z''' or '''Zulu''' time. A time may be written as e.g. 21:45Z with the Z indicating UTC. The "Z" is for "zero", and "Zulu" is the two-way radio pronunciation of "Z". It comes from the nautical system in which each time zone was assigned a letter.

Time zones east of UTC and west of the International Date Line are specified by the number of hours ''ahead'' of UTC (e.g. UTC+4); zones west of UTC and east of the Date Line are specified by the number of hours ''behind'' UTC (e.g. UTC-6). Crossing the Date Line going eastward, clocks are turned back a full 24 hours, and vice versa in the opposite direction. (Note: The total span of time zones covers more than 24 hours because the Date Line jogs westward and eastward to keep certain national island groupings on the same calendar day, although they are not within a single time zone.)

UTC+14

  • Kiribati Line Islands (''except U.S. dependencies - see UTC-11'')
  • UTC+13:45

  • New Zealand: Chatham Islands (''during Daylight Saving Time'')
  • UTC+13

  • Kiribati: Phoenix Islands
  • New Zealand (''during Daylight Saving Time'')
  • South Pole (''during Daylight Saving Time'')
  • Tonga
  • UTC+12:45

  • New Zealand: Chatham Islands
  • UTC+12

  • Fiji
  • Kiribati: Gilbert Islands
  • Marshall Islands
  • Nauru
  • New Zealand
  • Russia: Chukotka, Kamchatka
  • South Pole
  • Tuvalu
  • Wake Island
  • Wallis and Futuna
  • UTC+11:30

  • Australia: Norfolk Island
  • UTC+11

  • Australia: Australian Capital Territory, New South Wales, Tasmania, Victoria (''during Daylight Saving Time'')
  • Federated States of Micronesia: Kosrae, Pohnpei
  • New Caledonia
  • Russia: Kuril Islands, Magadan Oblast, Sakha
  • Solomon Islands
  • Vanuatu
  • UTC+10:30

  • Australia: South Australia (''during Daylight Saving Time'')
  • UTC+10

  • Australia ("Australian Eastern Time"): Australian Capital Territory, New South Wales, Queensland, Tasmania, Victoria
  • Federated States of Micronesia: Chuuk, Yap
  • Guam
  • Northern Mariana Islands
  • Papua New Guinea
  • Russia: Primorsky Krai, Khabarovsk Krai, Yakutia, Sakhalin Island
  • UTC+9:30

  • Australia ("Australian Central Time"): Northern Territory, South Australia
  • UTC+9

  • Australia Western Australia (''during Daylight Saving Time'')
  • East Timor
  • Indonesia (eastern): Maluku, Western New Guinea
  • Japan
  • North Korea
  • South Korea
  • Palau
  • Russia: Amur Oblast, Chita Oblast, Yakutia
  • UTC+8

  • Australia ("Australian Western Time"): Western Australia
  • Brunei
  • China (including Hong Kong and Macau)
  • Indonesia (central): (Bali, Borneo)
  • Malaysia
  • Mongolia (most of country)
  • Philippines
  • Singapore
  • Taiwan
  • Russia: Buryatia, Irkutsk Oblast
  • UTC+7

  • Cambodia
  • Christmas Island (Australia)
  • Indonesia (western): (Java, Sumatra)
  • Laos
  • Mongolia (Hovd, Uvs, and Bayan-Olgii)
  • Russia: Kemerovo, Khakassia, Krasnoyarsk Krai, Tomsk, Tuva
  • Thailand
  • Vietnam
  • UTC+6:30

  • Cocos Islands
  • Myanmar
  • UTC+6

  • Bangladesh
  • Bhutan
  • British Indian Ocean Territory (CIA)
  • Kazakhstan (Eastern)
  • Kyrgyzstan
  • Russia: Altai Krai, Altai Republic, Novosibirsk Oblast, Omsk Oblast, Tomsk Oblast
  • UTC+5:45

  • Nepal
  • UTC+5:30

  • India
  • Sri Lanka
  • UTC+5

  • British Indian Ocean Territory (NAO)
  • French Southern and Antarctic Lands
  • Heard Island and McDonald Islands
  • Kazakhstan (Western)
  • Maldives
  • Pakistan
  • Russia: Astrakhan, Bashkortostan, Chelyabinsk, Kurgan, Orenburg, Perm, Saratov, Sverdlovsk, Tyumen, Ulyanovsk, Volgograd
  • Tajikistan
  • Turkmenistan
  • Uzbekistan
  • UTC+4:30

  • Afghanistan
  • UTC+4

  • Armenia
  • Azerbaijan
  • Georgia
  • Mauritius
  • Oman
  • Reunion
  • Russia: Samara, Udmurtia
  • Seychelles
  • United Arab Emirates
  • UTC+3:30

  • Iran
  • UTC+3

  • Bahrain
  • Comoros
  • Djibouti
  • Eritrea
  • Ethiopia
  • Iraq
  • Kenya
  • Kuwait
  • Madagascar
  • Mayotte
  • Qatar
  • Russia: most of European portion, including Moscow, Saint Petersburg, Rostov on Don, Novaya Zemlya, Franz Josef Land, and all railroads throughout Russia
  • Saudi Arabia
  • Somalia
  • Sudan
  • Tanzania
  • Uganda
  • Yemen
  • UTC+2

  • Belarus
  • Botswana
  • Bulgaria
  • Burundi
  • Democratic Republic of the Congo (eastern)
  • Cyprus
  • Egypt
  • Estonia
  • Finland
  • Greece
  • Israel
  • Jordan
  • Latvia
  • Lebanon
  • Lesotho
  • Libya
  • Lithuania
  • Malawi
  • Moldova
  • Mozambique
  • Romania
  • Russia: Kaliningrad Oblast
  • Rwanda
  • South Africa
  • Swaziland
  • Syria
  • Turkey
  • Ukraine
  • Zambia
  • Zimbabwe
  • UTC+1

  • Albania
  • Andorra
  • Algeria
  • Angola
  • Austria
  • Belgium
  • Benin
  • Bosnia and Herzegovina
  • Cameroon
  • Central African Republic
  • Chad
  • Republic of the Congo
  • Democratic Republic of the Congo (western)
  • Croatia
  • Czech Republic
  • Denmark
  • Equatorial Guinea
  • France
  • Gabon
  • Germany
  • Gibraltar
  • Hungary
  • Italy
  • Liechtenstein
  • Luxembourg
  • Republic of Macedonia
  • Malta
  • Monaco
  • Montenegro
  • Namibia
  • Netherlands
  • Niger
  • Nigeria
  • Norway
  • Poland
  • San Marino
  • Serbia
  • Slovakia
  • Slovenia
  • Spain
  • Sweden
  • Switzerland
  • Tunisia*
  • Vatican City
  • UTC

  • Burkina Faso
  • Bouvet Island
  • Canary Islands
  • Cote d'Ivoire
  • Faroe Islands
  • Gambia
  • Ghana
  • Greenland (northeastern)
  • Guernsey
  • Guinea
  • Guinea-Bissau
  • Iceland
  • Ireland
  • Isle of Man
  • Jersey
  • Liberia
  • Mali
  • Mauritania
  • Morocco
  • Northern Ireland
  • Portugal
  • Saint Helena
  • Senegal
  • Sierra Leone
  • Sao Tome and Principe
  • Togo
  • United Kingdom
  • Western Sahara
  • UTC-1

  • Azores (Portugal)
  • Cape Verde
  • Greenland (east)
  • UTC-2

  • Fernando de Noronha (Brazil)
  • South Georgia and the South Sandwich Islands
  • Trindade and Martim Vaz (uninhabited islands) (Brazil)
  • UTC-3

  • Argentina
  • Brazil: Brasilia, Rio, Sao Paulo, Fortaleza, Maceio, Recife, Salvador etc.
  • French Guiana
  • Greenland (central)
  • Guyana
  • Saint Pierre and Miquelon
  • Suriname
  • Uruguay
  • UTC-3:30

  • Canada ("Newfoundland Time"): Newfoundland and Labrador
  • UTC-4

  • Anguilla
  • Antigua and Barbuda
  • Aruba
  • Barbados
  • Bermuda
  • Bolivia
  • Brazil: Boa Vista, Campo Grande, Manaus
  • Canada ("Atlantic Time"): Labrador, New Brunswick, Nova Scotia, Prince Edward Island, eastern Quebec
  • Chile
  • Dominica
  • Dominican Republic
  • Falkland Islands
  • Greenland (west)
  • Grenada
  • Guadeloupe
  • Guyana
  • Martinique
  • Montserrat
  • Netherlands Antilles
  • Paraguay
  • Puerto Rico
  • Saint Kitts and Nevis
  • Saint Lucia
  • Saint Vincent and the Grenadines
  • Trinidad and Tobago
  • Virgin Islands
  • UTC-4:30

  • Venezuela
  • UTC-5

  • Bahamas
  • Brazil: Acre
  • Canada ("Eastern Time"): Nunavut, most of Ontario, most of Quebec
  • Cayman Islands
  • Colombia
  • Cuba
  • Ecuador
  • Haiti
  • Jamaica
  • Navassa Island
  • Panama
  • Peru
  • Turks and Caicos Islands
  • United States of America ("Eastern Time"): Maine, New Hampshire, Vermont, New York, Massachusetts, Connecticut, Rhode Island, Michigan,except extreme northwestern counties Indiana except the southwest corner, Ohio, Pennsylvania, New Jersey, eastern Kentucky, West Virginia, Virginia, Washington, D.C., Maryland, Delaware, eastern Tennessee, North Carolina, Georgia, South Carolina, Florida except western part of panhandle.
  • UTC-6

  • Belize
  • Canada ("Central Time"): Manitoba, Saskatchewan, north-western Ontario
  • Costa Rica
  • Easter Island
  • El Salvador
  • Galapagos Islands
  • Guatemala
  • Honduras
  • Mexico
  • Nicaragua
  • United States of America ("Central Time"): Wisconsin, Illinois, the southwest corner of Indiana, western Kentucky, western and middle Tennessee, Mississippi, Alabama, Minnesota, Iowa, Missouri, Arkansas, Louisiana, north and east North Dakota, eastern South Dakota, middle and eastern Nebraska, most of Kansas, Oklahoma, most of Texas, part of western Florida(panhandle).
  • UTC-7

  • Canada ("Mountain Time"): Alberta, small eastern portion of British Columbia
  • Mexico: Baja California Sur: Chihuahua, Nayarit, Sinaloa, Sonora
  • United States of America ("Mountain Time"): southwest North Dakota, western South Dakota, western Nebraska, a sliver of Kansas, Montana, a sliver of Oregon, southern Idaho, Wyoming, Utah, Colorado, Arizona, New Mexico, a corner of Texas
  • UTC-8

  • Canada ("Pacific Time"): most of British Columbia, Yukon
  • Clipperton Island
  • Mexico: Baja California Norte
  • Pitcairn Islands
  • United States of America ("Pacific Time"): Washington, northern Idaho, most of Oregon, California, Nevada
  • UTC-9

  • French Polynesia: Gambier Islands
  • United States of America: most of Alaska
  • UTC-9:30

  • French Polynesia: Marquesa Islands
  • UTC-10

  • Cook Islands
  • French Polynesia: Society Islands, Tuamotu Islands, Austral Islands
  • Johnston Atoll
  • Tokelau
  • United States of America: Hawaii, and Aleutian Islands in Alaska
  • UTC-11

  • American Samoa
  • Jarvis Island, Kingman Reef, Palmyra Atoll
  • Midway Islands
  • Niue
  • Samoa
  • UTC-12

  • Baker Island
  • Howland Island