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Time Zones Converter

Created by Álvaro Díez
Reviewed by Bogna Szyk and Adena Benn
Last updated: Jun 05, 2023

The world is a big place, with many different time zones, so many that it is almost impossible to keep track of all of them unless you have a time zone converter. That's why our time zones converter (or world clock converter) is such a helpful tool. It allows you to calculate any date and time in any time zone - no matter what time zone you are interested in. Now, let's dig a bit deeper into the different time zones.

Why do we use time zones?

Many might be asking this question, and we think it's important to answer it to at least make a point for the use of the time zones converter. There are many ways in which we can keep track of time. Computers deal with time using what is called Unix time or epoch time, which basically means counting seconds from a fixed date and time, as we have explained in depth in the Unix time converter. Another way of timekeeping could be counting days instead of seconds, like what you can do with the day counter. However, that leads to the question of how do you define a day.

Historically, the way we humans have kept track of the date and time has been by looking at the sky. The date was more or less given by the apparent movement of the stars in the sky, whilst the time was taken by looking at the sun. The movement of the sun in the sky is periodic, so a complete rotation of the sun (in reality, this movement is due to the Earth spinning and not the sun moving) takes what we call a day; by dividing that period of time by 24, we get hours. From this, one could tell the time by just looking at the sun and its position in the sky.

In reality, the Earth is round, which means that the position of the sun at a given time depends on our position on the Earth. In an attempt to organize this difference while still keeping a certain relation between the date and time with the position of the sun in the sky, the time zones were born.

The world time zones try to group areas with the same solar time and give them a common date and time. Changes in "clock-time" are done abruptly in 1h steps around the globe according to the position of the country, avoiding having millions of time zones with very small differences between them. In reality, there are country borders, politics, and economic interests and fights, which means that not all countries actually keep their geographical time zone, and some even made their own with half an hour difference.

All in all, this is a universally accepted and very effective way to coordinate the entire world despite the differences in solar time. As we will see next, the most important time zone is the UTC time zone, which is the reference point for all other time zones. The rest of the time zones, be them American time zones, European time zones, or Asian time zones... are always referred to and defined by the time difference with respect to the UTC time zone.

How to use the time zones converter

Using the time converter is very easy and doesn't require a big knowledge of the different world time zones. Let's illustrate how you can use it as a world clock converter by looking at a specific example in which we want to convert the date and time from the New York time zone (US time zone called EST) to the UTC time zone:

  1. Look for the New York time zone abbreviation in the text below.
  2. Input the date and time we want to convert from into the box labeled EST (American time zone corresponding to New York time zone) in the time converter.
  3. Look for the UTC time zone where the answer will be already displayed.

It is not easy to memorize all abbreviations for each of the world's time zones and what cities and countries belong to which time zone; but, luckily for you, this knowledge is not required because we have compiled a list with all time zones available in this world clock converter. In addition to the list of all the world time zones, we included some comments and major cities in each of the time zones in the time converter, as well as a world time zones map for further reference in case you need it.

All world time zones explained

Time zones are, as we said previously, geographical areas with less than a 1h difference in their solar time. At least that's the ideal case; in reality, the world time zones map is more complicated and requires a longer explanation. Let's start with the naming conventions. There are 3 basic ways to name each time zone: by their time difference with respect to GMT or UTC time zone; the military nomenclature, which uses the letters of the alphabet; and the 'standard' abbreviations, which are 3 letters representing the official name (or names) that someone has given to the time zone.

Despite it being the messiest, the 'standard' abbreviations are the most common ones, including some that you might be familiar with such as the American time zones CST, PST, EST, the European CET, and GMT/UTC time zone... We will dive deeper into all the abbreviations in the next sections. On the other side of the spectrum, we have the very logical (almost robotic) military zones and time difference nomenclature that easily gives an idea of the geographical location of the time zone but contains no information about the countries or cities that it applies to.

It would be ideal if all time zones followed these simple rules of naming and 1h time difference between them, but nothing is perfect. There are also time zones that have time differences of half an hour with respect to other world time zones. To make matters worse, some countries shift their time zones during summer for supposed daylight savings. These 'irregularities' complicate everything but also make this time zone converter even more useful. It is also useful to have on hand a time zone map (like the one below) to know more accurately what geographical region uses which time zone.

World time zones map.

Universal Time Coordinated (UTC time zone) and international date line (IDL)

If we would have to choose one time zone that stands out of the rest due to its importance, it would be the Universal Time Coordinated (UTC) time zone. This is the reference point for all other time zones. It's also referred to as Greenwich Meridian Time or GMT because it contains the 0th terrestrial meridian that passes through Greenwich. This time zone includes places like Great Britain, Portugal, Iceland, and the north-west coast of Africa (Morocco, Mali, Ghana...).Hence, it is the reference time zone in this time zone converter.

The UTC time zone is the reference for the names of all other time zones in both the time difference and the military naming schemes. The time difference is referenced with respect to the GMT/UTC time zone, with all the world time zones having an increasing negative difference (-1h, -2h, -3h...) to the west and an increasing positive time difference to the east (+1h, +2h...). On the other hand, military time zones start with the letter A assigned to the UTC+1 time zone (CET) and move up the alphabet to the east until the letter M and then assigns the letter N to GMT/UTC time zone and goes up the alphabet to the west up to letter Y.

Another important time zone (or rather a time zone division) is the so-called International Date Line (IDL) which is located in the Pacific Ocean and marks the separations between one day and the next. It is on the opposite side of the Earth to the Greenwich meridian, and crossing this line means literally changing the date.

Eastern time zones by time difference

  • CET/WAT [GMT+1]
    Central European Time / West Africa Time - Includes most European countries, from Spain to Poland. It also includes the central part of Africa and its coast (Algeria, Cameroon, Angola...). Military zone A
  • EET/USZ1 [GMT+2]
    Easter European Time / Kaliningrad Time B - Includes eastern Europe (except Belarus), Eastern Mediterranean countries, and the south of Africa. Military zone B
  • MSK/EAT [GMT+3]
    Moscow Time / East Africa Time - Includes Belarus and the western part of Russia, Turkey, the easternmost part of Africa, and most of the Arabic peninsula. Military zone C
  • IRST [GMT+3:30]
    Iran Standard Time - Iran's own time zone
    Samara Time / Azerbaidjan Time / Armenia Time / Georgia Time / Mauritius Time - Includes the obvious countries, the easternmost part of the Arabic peninsula, and other archipelagos next to Mauritius. Military Zone D
  • AFT [GMT+4:30]
    Afghanistan Time - Afghanistan's own time zone
    Pakistan Time / Yekaterinburg Time / Maldives Time - Includes Pakistan, the Maldives, and most of the Asian countries to the north of Pakistan, as well as part of Russia. Military zone E
  • IST [GMT+5:30]
    Indian Standard Time - India's own time zone.
  • NPT [GMT+5:45]
    Nepal Time - Nepal's own time zone.
  • OMSK/BST [GMT+6]
    Omsk Time / Bangladesh Standard Time - Includes Bangladesh, Kazakhstan, Kyrgyzstan. Military Zone F
  • MMT [GMT+6:30]
    Myanmar Time - Burma's own time zone
  • CXT/KRAT [GMT+7]
    Christmas Island (Australia) Time / Krasnoyarsk Time - Includes Thailand, Laos, Vietnam, Cambodia, and the Indonesian area around Jakarta, as well as part of Russian and western Mongolia. Military Zone G
    Irkutsk Time / Chinese Standard Time / Australian Western Standard Time / Western Standard Time - Includes part of Russia, eastern Mongolia, China, Taiwan, Philippines, part of Indonesia, Malaysia, and the west coast of Australia. Military Zone H
  • JST/YAKT [GMT+9]
    Japan Standard Time / Yakutsk Time - Includes part of Russia, North Korea, South Korea, and Japan. Military Zone I
  • ACST/CST [GMT+9:30]
    (Australian) Central Standard Time - Central Australia's own time zone
    East (Australian) Standard Time / Vladivostok Time - Includes part of Russian, Federated States of Micronesia, Papua New Guinea, and the east coast of Australia. Military zone K
  • SAKT [GMT+11]
    Sakhalin Time - Includes part of Russia and countries in the Tasman Sea (Solomon Islands, Vanuatu...). Military Zone L
  • NFT [GMT+11:30]
    Norfolk Time - Includes said region of Australia
    International Date Line East / New Zealand (Standard) Time / Magadan Time - Includes the easternmost region of Russia, New Zealand, and several archipelagos in the Pacific. It is the easternmost time zone and, therefore, the first part of the world to start a new day. Military Zone M

Western time zones by time difference

  • AZOT/CVT [GMT-1]
    Azores Time / Cape Verde Time - Includes the Azores, Cape Verde, and a bit of Greenland, Military zone N

  • GST [GMT-2]
    South Georgia Time - Includes a few islands in the Atlantic Ocean. Military zone O

  • ART [GMT-3]
    Argentina time - Includes most of Greenland, Argentina, Uruguay, and part of Brazil. Military Zone P

  • NST [GMT-3:30]
    Newfoundland Standard Time - Newfoundland Island's own time zone.

  • AST/AT [GMT-4]
    Atlantic (Standard) Time - Includes the very easternmost parts of North America and some Caribbean islands as well as the central part of south America and Chile. Military zone Q

  • EST [GMT-5]
    Eastern Standard Time - Includes most of eastern North and South America, as well as the westernmost Caribbean islands and western South America. Military zone R

  • CST [GMT-6]
    Central Standard Time - Includes the central-east part of North America, as well as Central America. Military zone S

  • MST [GMT-7]
    Mountain Standard Time - Includes the central-west part of North America. Military zone T

  • PST [GMT-8]
    Pacific Standard Time - Includes North America's westernmost part (pacific coast) (except Alaska). Military zone U

  • AKST [GMT-9]
    Alaska Standard Time - Includes Alaska. Military zone V

  • HST [GMT-10]
    Hawaii Standard Time - Includes Hawaii Islands, French Polynesia, and other islands in the Pacific ocean. Military zone W

  • NUT [GMT-11]
    Niue Time - Includes Jarvis island and other islands in the Pacific ocean. Military zone X

  • IDLW [GMT-12]
    International Date Line West - Line dividing one day from another. Military zone Y

Summer time zones

    British Summer Time / Irish Summer Time / Western European Summer Time
  • CEST [GMT+2]
    Central European Summer Time
  • EEST [GMT+3]
    East Europe Summer Time
  • IRDT [GMT+4:30]
    Iran Daylight Time
  • WADT [GMT+8]
    West Australia Daylight Time
  • ACDT/CDT [GMT+10:30]
    (Australia) Central Daylight Time
  • EADT/EDT [GMT+11]
    East (Australia) Daylight Time
  • NZDT [GMT+13]
    New Zealand Daylight Time
  • NDT [GMT-2:30]
    Newfoundland Daylight Time
  • ADT [GMT-3]
    Atlantic Daylight Time
  • EDT [GMT-4]
    Eastern Daylight Time
  • CDT [GMT-5]
    Central Daylight Time
  • MDT [GMT-6]
    Mountains Daylight Time
  • PDT [GMT-7]
    Pacific Daylight Time
  • AKDT [GMT-8]
    Alaska Daylight Time
  • HDT [GMT-9]
    Hawaii Daylight Time

Final notes and tricks

When using the time zones converter, there are a couple things that can be helpful.

First of all, for simplicity, only a few time zones are shown by default in the time zones converter, but if you click on Advanced Mode you will be able to see all existing time zones as well as summer time zones for these countries which have daylight savings time. It is also interesting to know that hovering the mouse over the time zones in the time zones converter will bring up a small help dialog with basic information about the time zones in question.

Álvaro Díez
Reference Time
Eastern Time Zones
Western Time Zones
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