International Date Line
The international date line serves as a “line of demarcation” between two calendar dates. When you cross the date line, you become a sort of time traveler! When you cross to the west, it’s one day later; when you cross back, you’ve “gone back in time.”
What is International Date Line?
The international date line (IDL) is an imaginary line that runs from the North Pole to the South Pole in the middle of the Pacific Ocean. When you cross it, depending on which direction you are traveling, you gain or lose a day. When traveling westward, you gain a day; when traveling eastward, you lose a day. The time at this longitude is exactly 12 hours from the 0° longitude, irrespective of whether one travels westward or eastward from the Prime Meridian. The international date line passes through the mid-Pacific Ocean and roughly follows a 180 degrees longitude north-south line on the Earth.
International Date Line Definition
The international date line, established in 1884, is an imaginary line on the surface of the Earth that demarcates the change of a calendar day. It is the anti-meridian or 180th meridian of the modern Prime Meridian. The time difference on either side of this line is 24 hours. It is located halfway around the world from the prime meridian — the 0 degrees longitude line in Greenwich, England.
International Date Line passes through?
The International Date Line passes through the middle of the Pacific Ocean. It does not cross any country. This was done because the date changes when crossing the date line. If the International Date Line had crossed any country’s land, it would have caused confusion as the eastern part of the country towards Japan separated by the date line would have been a calendar day ahead of the western part towards North America. This is also why the International Date Line has a zigzag pattern. It has avoided crossing any country or significant landmass by maintaining a zigzag line.
International Date Line on the globe
Looking at the International Date Line on the globe, we see that the line runs from the North Pole to the easternmost part of Russia. It falls to the west of Hawaii, keeping the island relatively close to the rest of the country in terms of time zones. It then travels further south through the Pacific Ocean before turning east to encompass the Kiribati Islands. The line continues to the south, passing through New Zealand until it reaches Antarctica and the South Pole. In the mid-Pacific, it curves from the normal 180° meridian at the Bering Strait, Fiji, Tonga, and other islands to prevent confusion of day and date in some of the island groups that are cut through by the meridian.
International Date Line longitude
The proposed International Date Line longitude is 180 degrees, and this puts the International Date Line coordinates exactly halfway around the world from another imaginary line of demarcation called the Prime Meridian. The time zones on either side of the International Date Line are either twelve hours ahead of the time zone at the Prime Meridian (in the territories to the west of the International Date Line), or twelve hours behind it (to the east of the line).
International Date Line : FAQs
Q1. Why is International Date Line not straight?
Ans. The International Date Line is not perfectly straight because it has been adjusted to allow nations to stay on either side of the line. Splitting countries into two different dates causes a lot of confusion. When the date line was first established, Kiribati was split on both sides, but they later changed their calendars so that everyone was in the same time zone, forcing the International Date Line to shift significantly to the east.
Q2. What happens when you cross International Date Line?
Ans. When you cross the IDL, you either gain or lose a day depending on which way you are traveling. If you are traveling westward, you gain a day, and if you are traveling eastward, you lose a day.
Q3. International Date Line passes through which ocean?
Ans. International Date Line passes through the mid-Pacific Ocean.