At the North and South Pole, all lines of longitude converge, so they do not have their time zones.


What Is a Time Zone?

In the geographic coordinate system, a type of imaginary vertical line called longitude connects the North and South poles, dividing the globe into several time zones. A time zone is a region of the Earth that observes a standard time for social, commercial, and legal purposes. It is set according to the offset from one Coordinated Universal Time (UTC), which starts at the Prime Meridian at zero degrees longitude.

Based on this system, the Earth is divided vertically into 24 time zones with an hour difference roughly 15 degrees apart. A country or region can have multiple time zones. The U.S., for example, is spread across six time zones.

In other words, the lines of longitude determine the local time, which is synchronized to the position of the Sun in the sky. However, this system does not apply at the North and South poles, where the Sun's rising and setting occurs only once a year. Because of this, day and night are not as separated as they are near the equator.

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How Is Time Determined at the Poles?

All lines of longitude converge at the poles, which means that the poles are technically located within all time zones simultaneously. But how is time determined in these areas?

A person at the North Pole can use any time as the local time, and no one will disagree. It is not hard to think about a place where a single person can decide to create their own time since no one practically lives there.

Unlike other regions or countries, the North Pole is not defined by any border or boundary. It is impossible to mark the exact location of the North Pole because it is in the middle of the Arctic Ocean with shifting sea ice. It is rarely visited for research purposes by a vessel or supply ship that mistakenly strayed from elsewhere.

In such a zone where there is no sense of time, the captains of the research vessel or strayed ship choose their own time. They can use bordering countries' time zones or switch them based on ship activities. They can even observe the same time zone as their country of origin.

Meanwhile, marking the exact point of the South Pole is easier since it is located in Antarctica. There are no permanent residents in this continent, but there are around 5,000 people in the summer, composed of scientists operating research stations, and about 1,000 in the winter.

They must agree to their time zones for practical purposes to determine when to sleep or work. In this part of the world, time zones are generally set to match the time zone of the country that operates or supplies them. For instance, the Amundsen-Scott Pole Station operates on New Zealand time (GMT +12), so visitors adopt this time, too.

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