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International Date Line Boundry?
Whats that for?
- HeatherLv 58 years agoFavorite Answer
The International Date Line (IDL) is an imaginary line on the surface of the Earth from the north to the south pole and demarcates one calendar day from the next. It passes through the middle of the Pacific Ocean, roughly following the 180° longitude but it deviates to pass around some territories and island groups.
The IDL is on the opposite side of the Earth to the Prime Meridian. The Prime Meridian helps to define Universal Time and is the meridian from which all other time zones are calculated. Time zones to the east of the Prime Meridian are in advance of UTC (up to UTC+14); time zones to the west are behind UTC (to UTC-12).
The IDL and the moving point of midnight separate the two calendar days that are current somewhere on Earth. However, during a two-hour period between 10:00 and 11:59 (UTC) each day, three different calendar days are in use. This is because of daylight saving in the UTC+12 zone and the use of additional date-shifted time zones in areas east of the 180th meridian. These additional time zones result in the standard time and date in some communities being 24 or 25 hours different from the standard time and date in others.
A traveler crossing the IDL eastbound subtracts one day, or 24 hours, so that the calendar date to the west of the line is repeated after the following midnight. Crossing the IDL westbound results in 24 hours being added, advancing the calendar date by one day. The IDL is necessary to have a fixed, albeit arbitrary, boundary on the globe where the calendar date advances in the westbound direction.
- obviousLv 48 years ago
If you travel east around the world, you keep losing hours, one time zone at a time. When you get back home, you will have lost 24 hours, and be a day ahead of everyone else. So, somewhere, there has to be a line that you cross when going around the world where you get a day back.
That line (the International Date Line) was deliberately picked where it would affect the least number of people. You might notice that the line zig zags so that all of Russia is on one side, and all of Alaska on the other.
This phenomenon of gradually losing a day is central to the plot outcome of the movie "Around the World in 80 Days".
It's a fun movie, you can probably get it on cable TV occasionally.Source(s): http://www.imdb.com/title/tt0048960/
- KennyBLv 78 years ago
The earth is round and there are 24 times zones in it. Somewhere, there must be a point at which the date changes.
International convention put that line in the middle of the Pacific Ocean such that Russia is (almost) always a day ahead of Alaska.
- 5 years ago
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