PT to MDT to CT to ET to GMT to London, United Kingdom to Copenhagen, Denmark to Istanbul, Turkey to IST to CST Asia

Pacific Time (PT) is a general term used to describe the areas that observe either the Pacific Standard Time (PST) or Pacific Daylight Time (PDT) in the United States and Canada. PT also called Pacific Coast Time. PT is not static but switches between PDT and PST.

Territories observing the Pacific Time Zone are primarily in North America. It runs through the western part of Canada, the United States and the Northwestern part of Mexico.

Countries using this time zone: Canada, Mexico, United States.

Principal Cities: The largest city in the PST time zone is Los Angeles in the United States, with about 3.793 million people. Other major cities in this time zone include Vancouver, Tijuana, San Diego, San Jose.

French: HNP - Heure Normale du Pacifique

Spanish: PT - Tiempo del Pacífico, PT - Zona Noroeste

Offset: MDT is 6 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Canada, Mexico, United States

Principal Cities: The largest city in the MDT time zone is Calgary in Canada, with about 1.02 million people. Other major cities in this time zone include Edmonton, El Paso, Denver, Albuquerque.

French: HAR - Heure Avancée des Rocheuses

Spanish: MT - Zona Pacífico

Central Time (CT) is a general term used to describe the areas that observe either the Central Standard Time (CST) or Central Daylight Time (CDT) in the United States and Canada. CT is not static but switches between CDT and CST.

Territories observing the time zone are primarily in North and Central America. It runs through several Mexican and U.S. states, as well as several Canadian provinces and Central American countries.

Countries using this time zone: Belize, Canada, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, El Salvador, United States.

Principal Cities: The largest city in the CST time zone is Mexico City in Mexico, with about 12.294 million people. Other major cities in this time zone include Chicago, Houston, Iztapalapa, Ecatepec.

French: HNC - Heure Normale du Centre

Spanish: CT - Tiempo Central Estándar, CT - Zona Centro

Eastern Time (ET) is a general term used to describe the areas that observe either the Eastern Standard Time (EST) or Eastern Daylight Time (EDT) in the United States and Canada. ET is not static but switches between EDT and EST.

ET is also used somewhat as a de facto official time for all of the United States because it encompasses 17 U.S. states in the eastern part of the contiguous United States including the capital city Washington D.C., the most populous city New York and half of the country’s population.

In the United States nationally televised programs, evening newscasts, talent and awards shows, and any other nationally televised event that airs live on American television during prime time and on the weekends are broadcast live in the Eastern Time Zone. Major professional sports leagues MLB, NBA, NFL and NHL also provide their game times in Eastern Time, even if teams are from outside of Eastern Time.

Countries using this time zone: Bahamas, Canada, Haiti, Jamaica, Cayman Islands, Mexico, Panama, Turks & Caicos Is, United States.

Principal Cities: The largest city in the EST time zone is New York City in the United States, with about 8.175 million people. Other major cities in this time zone include Toronto, Montreal, Brooklyn, Borough of Queens.

French: HNE - Heure Normale de l'Est

Spanish: ET - Tiempo del Este, ET - Zona Sureste

Offset: GMT is 0 hours ahead Greenwich Mean Time (GMT) and is used in Europe

Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo

Principal Cities: The largest city in the GMT time zone is London in United Kingdom, with about 7.557 million people. Other major cities in this time zone include Abidjan, Dakar, Grand Dakar, Accra.

Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use for the most parts it is the same. In military GMT is known as Zulu time.Greenwich Mean Time was the same as Universal Time (UT), until the introduction of UTC in 1972 a standard astronomical concept used in many technical fields.

Offset: IST is 5 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: India

Principal Cities: The largest city in the IST time zone is Mumbai in India, with about 12.692 million people. Other major cities in this time zone include Delhi, Bangalore, Kolkata, Chennai.

Daylight Saving: Clocks in India Standard Time (IST) do not change for daylight saving time, so IST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

Offset: CST is 8 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: China, Macau, Taiwan

Principal Cities: The largest city in the CST time zone is Shanghai in China, with about 14.609 million people. Other major cities in this time zone include Zhumadian, Taipei, Beijing, Nanchong.

Daylight Saving: Clocks in China Standard Time (CST) do not change for daylight saving time, so CST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.