International Date Line is the imaginary line that coincides with the meridian of longitude 180°, which crosses the Pacific Ocean. It was established as a way to standardize calendars on a world scale and thus facilitate timekeeping.
This line marks the boundary between one day and another, and crossing it results in the date changing. From west to east, we go back one day on the calendar. To advance, just cross it in the opposite direction, from east to west.
See too: Parallels and Meridians—What's the Difference?
Summary of the International Date Line
The International Date Line (LID) extends across the Pacific and corresponds to the meridian of longitude 180°.
It marks the passage of the day on the calendar, indicating the date change.
It also represents the far east and far west of the eastern and western hemispheres.
When we cross it from west to east, we go back one day on the calendar. From east to west, we move one day forward on the calendar.
Its establishment was important for the standardization of calendars on an international scale, creating a convention for counting time.
Its use facilitated the establishment of time zones and was fundamental in several aspects of international relations, as in trade, and everyday life, as in long-distance travel and communication. distance.
What is the International Date Line for?
The International Date Line plays a very important role in the delimitation of time and in the instrumentation of the time zone system. This imaginary line was instituted as a form ofdelimit the passage from one day to the next officially.
It sets an international standard that has made counting the passage of time across the globe much easier and more practical. In addition, it represents the eastern and western extremes of the eastern and western hemispheres, respectively.
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How does the International Date Line work?
The International Date Line (LID) is the meridian opposite the Mgreenwich eridian, therefore located at 180° longitude. It marks the boundary between one day and another on the calendar, a change that occurs through its crossing. Therefore, it works as follows:
West to East: when we cross that line from west to east, we go back one day on the calendar.
East to West: when we cross it in the opposite direction, from east to west, we advance one day.
Graphic representation of the International Date Line
The International Date Line is located in the Pacific Ocean, crossing it from the North Pole to the South Pole. Although it passes through a region of very low demographic density, your layout was adapted according to the territorial limits of the countries and islands that are on your way, as we see on the map, in order to avoid further inconvenience in these locations.
Know more: What is the Trans-Pacific Partnership Agreement (TPP)?
How important is the International Date Line?
The establishment of the International Date Line resulted from a series of problems that arose in logbooks during the Grandes navigations, at which time there was still no international convention for the determination of the counting of time in the planet.
Thus, the date change line is of fundamental importance worldwide, as it standardizes the international calendar and demarcates the passage of days, implying improvements in various aspects of daily life, especially with regard to long-distance travel, communication and international trade.
History of the International Date Line
As we have seen, the problems related to the counting of time began in the 16th century, a period characterized by the European majority of maritime expeditions that departed towards the Asia and the Americas called Great Navigations.
The discrepancies found in the travel records combined with the need to standardize the counting of hours resulted in a meeting that took place in 1884 in the city of Washington, capital of the United States. United States, call of International Meridian Conference.
The meeting of 1884 defined what would be the zero mark for the determination of the longitudes and also for the counting of the time zones, being the Greenwich Meridian (0°). The meridian on the opposite side would then be the 180° longitude meridian, which was called the International Date Line.
Its original layout was a little different from what we see today and, at first, not all countries adopted the new conventions. A series of changes were made to this imaginary line, in order to respect the territorial limits of the countries located in the Pacific, notably the island nations of the South Pacific.
The most recent changes took place in the last decade, more precisely at the end of December 2011, when the Polynesian countries of Samoa and Tokelau made changes to their time zone and moved from adopting Western Civil Time, in the American Standard, to Eastern Time.
By Paloma Guitarrara
Geography teacher
Would you like to reference this text in a school or academic work? Look:
GUITARRA, Paloma. "International Date Line"; Brazil School. Available in: https://brasilescola.uol.com.br/geografia/linha-internacional-da-data.htm. Accessed on February 07, 2022.
