Q:

How may time zones are there in the world?

A:

Quick Answer

There are 24 different time zones in the world set at 15 degree longitude intervals in between. The Earth completes one full rotation in 24 hours at a speed of 15 degrees per hour. The premise behind time zones is that the world is theoretically divided into 24 equal longitudinal zones and the time is accordingly adjusted in each zone by an hour.

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How may time zones are there in the world?
Credit: NASA Goddard Space Flight Center CC-BY 2.0

Full Answer

Since most communities around the world refer to noon as the time of the day when the sun is at its peak, noon may occur at different times in different countries depending on their location. While this did not pose many problems in the past, advancements in transportation, communication and global trade created the need for a standardized global time-keeping system.

The idea of establishing time zones was proposed by Sir Sanford Fleming in the late 1800s, but it was only in 1929 when it was instituted worldwide. Its implementation had minimal effect on the traditional way of telling the time in each zone and made it easier for people to understand the time differences between the zones.

The main reference point for the different time zones is the Greenwich Meridian located in the Royal Observatory in Greenwich, England. It is more popularly referred to as the Greenwich Mean Time or GMT. The GMT has since been replaced with the term Coordinated Universal Time abbreviated as UTC.

The UTC is the starting point from which the times in the different countries around the world are determined. The time differences are indicated by "+" or "-" the number of hours or time zones in relation to the UTC as the starting point.

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Related Questions

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    How do you determine the current time at different places in the world?

    A:

    Time around the world is calculated using time zones. There are 24 time zones, which each are labeled as a number ahead of or behind the "center" time zone in Greenwich, England. Find the time around the world by taking the time at one location and then adding or subtracting the time zone difference between the two locations.

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    What does 9/8c mean?

    A:

    When discussing time zones, 9/8c denotes a time when it is 9 o'clock in the Eastern time zone and 8 o'clock in the central time zone of the United States and Canada. Those times happen simultaneously, but the clock reads different times in different longitudes.

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    How do you find out the current time in different time zones?

    A:

    Find the current time in different time zones by consulting TimeAndDate.com, WorldTimeZone.com or 24TimeZones.com. As of 2015, all sites give the present time all over the world; the first one by the name of the city or country and the second two by using maps.

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  • Q:

    What are the time zones in China?

    A:

    One time zone is used in China, even though the country covers five geographic time zones. China's time zone is eight hours ahead of Coordinated Universal Time, also known as Greenwich Mean Time. The westernmost part of China, Xinjiang Province, uses an unofficial time zone with time set at UTC+6:00.

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