Timezones and an explanation of the International Date Line. (Match the time bar color to the map color at the bottom). Print this map View time zone clocks. The International Date Line (IDL) is an imaginary line on Earth's surface defining the boundary between one day and the next. Time Zone map. Map showing the International Date Line. Source: Wiki Commons, Throughout the existence of the date line countries have merged time zones and.
Time and World Time Zones and time map with current time around the World on February 7 date and time in relation to other locations around the world /. (Fiji time zones map, Tuvalu time zones map, Tonga time zones map, International Date Line, French Polynesia time zones map, Wallis and Futuna time zones. The International Date Line, established in , passes through the mid-Pacific Ocean and roughly follows degrees longitude north-south line on the.
The International Date Line (IDL) is an imaginary line of demarcation on the surface of Earth on the most common understanding of the de facto International Date Line. See § De facto and de jure date lines below, and map above at right. Time and World Time Zones and time map with current time around the World on February 7 date and time in relation to other locations around the world /. International Date Line, also called Date Line, imaginary line extending between the North Pole and the South Pole and arbitrarily demarcating each calendar day from the next. It corresponds along most of its length to the th meridian of longitude but deviates eastward through.
International Date Linealso called Date Lineimaginary line extending between the Map Pole and the South Pole and arbitrarily demarcating each map day from the next. It corresponds along most of its length to the th meridian of longitude but deviates eastward through date Bering Strait to avoid dividing Siberia and international deviates westward to include the Aleutian Islands with Alaska.
South of the Equatoranother eastward deviation allows certain island groups to have the same day as New Zealand. The International Date Line is a consequence of the worldwide use of date systems arranged so that local noon corresponds approximately to the time at which the sun crosses the local meridian of longitude see Standard Time. A traveler going completely around the world date carrying a clock that he advanced or set back by one hour whenever he entered a new time zone and international calendar that he advanced by one day whenever his clock indicated midnight would find on returning to his starting point that map date according to his international experience was different by one day from that kept by persons who had remained at the starting point.
The International Date Line provides a standard means of making the needed readjustment: travelers moving map across the map set their international back one day, and those traveling westward set theirs a day ahead. International Date Line. Article Media. Info Print Cite. Submit Feedback. Thank you for your feedback.
See Article History. International More in date related Britannica map. When one travels across international westward a calendar day is added; one day is dropped in passing eastward.
Map line also deviates from a straight path in places to accommodate national boundaries…. Time is the same throughout each zone and differs from the international basis of legal and date time, Map Universal Time, by an integral number of hours; minutes and seconds are the same. In a…. This geographic North Pole does not international with the magnetic Date Pole—to which magnetic compasses date and which in the early 21st century lay north of the Queen Elizabeth Islands….
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Be on the lookout date your Britannica newsletter to get trusted stories delivered right to your inbox. More About. Date from Britannica Encyclopedias international elementary and high school students.
Suspecting the lines may be sourced from time zones, I peeked at a time zone map and realized something: pretty much every existing map of the International Date Line is wrong. To be clear, the International Date Line is made up , with no true established standard.
Existing maps of the International Date Line are accurate in terms of dividing land up into proper time zones, but it completely ignores maritime sovereignty. From Wikipedia , so it must be true. Sovereignty is the driving force behind time zones, and therefore the International Date Line. As a sovereign nation they could , but for what purpose?
So I came up with a thought experiment: What if we redefined the International Date Line using maritime sovereignty? It makes sense, however, that the island nation as a whole would want to be on the same day. See those gray hairlines in the above image? Regardless of validity, those submissions should probably be on the same side of the International Date Line as the submitting nation. After the change, the IDL in effect moved eastwards to go around the entire country. Strictly legal, the nautical IDL convention is still valid.
When the land time zone says it's Monday, these islands would form enclaves of Monday in an ocean which has Sunday. Maps are usually not drawn this way. As a consequence of the change, Kiribati's easternmost territory, the Line Islands , including the inhabited island of Kiritimati Christmas Island , started the year before any other country, a feature the Kiribati government capitalized upon as a potential tourist draw.
Christmas for example, is celebrated on 25 December according to either the Gregorian or the Julian calendar , depending upon which of the two is used by the particular church as that date falls in countries located on either side of the Date Line. A problem with the general rule above arises in certain Christian churches that solemnly observe a Sabbath day as a particular day of the week, when those churches are located in countries near the Date Line.
Notwithstanding the difference in dates, the same sunrise happened over American Samoa as happens over Samoa a few minutes later, and the same sunset happens over Samoa as happened over American Samoa a few minutes earlier.
In other words, the secular days are legally different but they are physically the same; and that causes questions to arise under religious law. Because the Date Line was an arbitrary imposition, the question can arise as to which Saturday on either side of the Date Line or, more fundamentally, on either side of degrees longitude is the "real" Saturday. This issue which also arises in Judaism is a particular problem for Seventh Day Adventists, Seventh Day Baptists, and similar churches located in countries near the Date Line.
The Samoan Independent Seventh-day Adventist Church, which is not affiliated to the worldwide Seventh-day Adventist Church, has decided to continue worshiping on Saturday, after a six-day week at the end of In particular, the day for holding the Jumu'ah prayer appears to be local Friday everywhere in the world.
The IDL is not a factor in the start and end of Islamic lunar months. These depend solely on sighting the new crescent moon. That this day may vary in different parts of the world is well known in Islam. The concept of an international date line in Jewish law is first mentioned by 12th-century decisors. As a practical matter, the conventional International Date Line—or another line in the Pacific Ocean close to it—serves as a de facto date line for purposes of Jewish law, at least in existing Jewish communities.
However, there is not unanimity as to how Jewish law reaches that conclusion. For this reason, some authorities rule that certain aspects of Sabbath observance are required on Sunday in Japan and New Zealand or Friday in Hawaii and French Polynesia in addition to Saturday.
Additionally, there are differences of opinion as to which day or days individual Jews traveling in the Pacific region away from established Jewish communities should observe Shabbat. For individuals crossing the date line, the change of calendar date influences some aspects of practice under Jewish law.
Yet other aspects depend on an individual's experience of sunsets and sunrises to count days, notwithstanding the calendar date. The date line is a central factor in Umberto Eco 's book The Island of the Day Before , in which the protagonist finds himself on a becalmed ship, with an island close at hand on the other side of the IDL. Unable to swim, the protagonist indulges in increasingly imaginative speculation regarding the physical, metaphysical and religious importance of the date line.
The main protagonist, Phileas Fogg , travels eastward around the world. He had bet with his friends that he could do it in 80 days. The next day, however, it is revealed that the day is Saturday, not Sunday, and Fogg arrives at his club just in time to win the bet.
Verne explains:. In journeying eastward he [Fogg] had gone towards the sun, and the days therefore diminished for him as many times four minutes as he crossed degrees in this direction. There are three hundred and sixty degrees on the circumference of the earth; and these three hundred and sixty degrees, multiplied by four minutes, gives precisely twenty-four hours—that is, the day unconsciously gained.
In other words, while Phileas Fogg, going eastward, saw the sun pass the meridian eighty times, his friends in London only saw it pass the meridian seventy-nine times. Fogg had thought it was one day more than it actually was, because he had forgotten this simple fact. During his journey, he had added a full day to his clock, at the rhythm of an hour per fifteen degrees, or four minutes per degree, as Verne writes.
At the time, the concept of a de jure International Date Line did not exist. If it did, he would have been made aware that it would be a day less than it used to be once he reached this line. Thus, the day he would add to his clock throughout his journey would be thoroughly removed upon crossing this imaginary line.
But a de facto date line did exist since the UK, India and the US had the same calendar with different local times, and he should have noticed when he arrived to the US that the local date was not the same as in his diary his servant Jean Passepartout kept his clock in London time, despite the tips of his surroundings.
Ceremonies aboard ships to mark a sailor's or passenger's first crossing of the Equator, as well as crossing the International Date Line, have been long-held traditions in navies and in other maritime services around the world. The need for a temporal discontinuity on the globe can be described mathematically as following from the Borsuk-Ulam Theorem in dimension 1: It is a topological fact that there does not exist any continuous , one-to-one function mapping from a circle onto an interval.
From Wikipedia, the free encyclopedia. For other uses, see Dateline disambiguation. Further information: International date line in Judaism. See also: Line-crossing ceremony. The National Geographic Magazine. Retrieved 4 January Accessed 11 August Pacific Islands Report.
September Time and date. Retrieved 20 May , and click through to the individual stations' pages. With respect to Scott Base, see Ross Dependency. Retrieved 23 September Retrieved 20 May Note that this map uses the opposite sign convention for time zones from that used in Wikipedia.
Downing, "Where the day changes" , Journal of the British Astronomical Association , vol x, no 4, , pp. October, Protocols of the proceedings". Project Gutenberg. Quote is from the session of 14 October. Retrieved 30 December An illustrated manual for the use of the terrestrial and celestial globes. New York. The transfer of territory from Russia to the United States , Executive document in Executive documents printed by order of the House of Representatives during the second session of the fortieth Congress, —'68 , vol.
Sumner released the written version of his speech on Thursday, 24 May , having written it during the immediately preceding Congressional recess following notes on a single page that he actually used on Tuesday, 9 April. Associated Press via the New York Post. Archived from the original on 31 December Retrieved 11 August BBC News. Retrieved 27 November Accessed 4 January New York Times.
Retrieved 24 September Retrieved 2 January