Editing International Date Line (section)

===Description===
{{refimprove section|date=July 2022}}
:''This description is based on the most common understanding of the ''de facto'' International Date Line. See {{slink||De facto and de jure date lines}} below, and map above at right.''
The IDL is roughly based on the [[Meridian (geography)|meridian]] of 180° longitude, roughly down the middle of the Pacific Ocean, and halfway around the world from the [[IERS Reference Meridian]], the successor to the historic [[Prime meridian (Greenwich)|Greenwich prime meridian]] running through the [[Royal Observatory, Greenwich|Royal Greenwich Observatory]]. In many places, the IDL follows the 180° meridian exactly. In other places, however, the IDL deviates east or west away from that meridian. These various deviations generally accommodate the political and economic affiliations of the affected areas.

Proceeding from north to south, the first deviation of the IDL from 180° is to pass to the east of [[Wrangel Island]] and the [[Chukchi Peninsula]], the easternmost part of Russian [[Siberia]]. (Wrangel Island lies directly on the meridian at 71°32′N 180°0′E, also noted as 71°32′N 180°0′W.)<ref name="wrengell">{{cite journal |title=Arctic Expeditions Commanded by Americans |journal=The National Geographic Magazine |volume=18 |pages=459–468 |url=https://books.google.com/books?id=_RAOAQAAIAAJ&pg=PA459|year=1907 |access-date=4 January 2017}}</ref> It then passes through the [[Bering Strait]] between the [[Diomede Islands]] at a distance of {{convert|1.5|km|mi}} from each island at 168°58′37″ W.<ref name="Russia-US maritime boundary">{{citation |last=Allen |first=Jared |date=11 January 2012 |title=United States – Russian Maritime Boundary and Exclusive Economic Zones |website=ArcticEcon |url=https://arcticecon.wordpress.com/2012/01/11/united-states-russian-maritime-boundary-and-exclusive-economic-zones/ |access-date=4 January 2017 |archive-date=5 January 2017 |archive-url=https://web.archive.org/web/20170105181513/https://arcticecon.wordpress.com/2012/01/11/united-states-russian-maritime-boundary-and-exclusive-economic-zones/ |url-status=live }}</ref> It then bends considerably west of 180°, passing west of [[St. Lawrence Island]] and [[St. Matthew Island]].

The IDL crosses between the U.S. [[Aleutian Islands]] ([[Attu Island]] being the westernmost) and the [[Commander Islands]], which belong to Russia. It then bends southeast again to return to 180°. Thus, all of Russia is to the west of the IDL, and all of the United States is to the east except for the insular areas of [[Guam]], the [[Northern Mariana Islands]], and [[Wake Island]], reaching the hypothetical, but not used UTC–13:00 time zone.

The IDL remains on the 180° meridian until passing the [[equator]]. Two U.S.-owned uninhabited atolls, [[Howland Island]] and [[Baker Island]], just north of the equator in the central Pacific Ocean (and ships at sea between 172.5°W and 180°), have the ''earliest''{{efn|'''Earliest time on Earth''' here means that calendar day and clock time in this [[time zone]] is ''least'' advanced (or the {{nowrap|"{{em|oldest}}{{tsp}}")}} on Earth and that this place is the ''last'' {{nowrap|(''latest''{{tsp}})}} on Earth to reach any day and time. Because of that this time zone ([[UTC−12:00|IDLW]]) is sometimes also called [[Anywhere on Earth]] and deadlines can be set based on it e.g. "until the end of day Anywhere on Earth" means that if the day ended there it also ended everywhere else on the planet before that.<ref>{{Cite web|url=http://www.ieee802.org/16/aoe.html|title=IEEE 802.16 AOE Deadline Documentation|website=ieee802.org}}</ref>}} time on Earth ([[UTC−12:00]] hours).{{r|timeNearIDL1}}

The IDL circumscribes [[Kiribati]] by swinging far to the east, almost reaching the [[150th meridian west|150°W meridian]]. Kiribati's easternmost islands, the southern [[Line Islands]] south of [[Hawaii]], have the ''latest''{{efn|'''Latest time on Earth''' here means that calendar day and clock time in this [[time zone]] is ''most'' advanced (or the "''newest''") on Earth and that this place is the ''first'' (''earliest'') on Earth to reach any day and time.}} time on Earth ([[UTC+14:00]] hours).{{r|timeNearIDL1}}

South of Kiribati, the IDL returns westward but remains east of 180°, passing between [[Samoa]] and [[American Samoa]].<ref name=BorneoPost>[http://www.theborneopost.com/2011/06/30/samoa-confirms-dateline-switch/ Samoa confirms dateline switch] {{Webarchive|url=https://web.archive.org/web/20111008180735/http://www.theborneopost.com/2011/06/30/samoa-confirms-dateline-switch/ |date=8 October 2011 }} Borneo Post online. Accessed 11 August 2011.</ref> Accordingly, Samoa, [[Tokelau]], [[Wallis and Futuna]], [[Fiji]], [[Tonga]], [[Tuvalu]], and New Zealand's [[Kermadec Islands]] and [[Chatham Islands]] are all west of the IDL and have the same date. American Samoa, the [[Cook Islands]], [[Niue]], and [[French Polynesia]] are east of the IDL and one day behind.

The IDL then bends southwest to return to 180°. It follows that meridian until reaching [[Antarctica]], which has [[Time in Antarctica|multiple time zones]]. Conventionally, the IDL is not drawn into Antarctica on most maps. (See {{slink||Cartographic practice and convention}} below.)