International Date Line

International Datelinedate linedatelineModern CartographySamoa and Tokelau's dateline shift
The International Date Line (IDL) is an imaginary line of demarcation on the surface of Earth that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next.wikipedia
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Wrangel Island

Natural System of Wrangel Island ReserveWrangelWrangel Island arctic desert
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.
The International Date Line is displaced eastwards at this latitude to avoid the island as well as the Chukchi Peninsula on the Russian mainland.

Aleutian Islands

AleutiansAleutianAleutian Chain
The IDL crosses between the U.S. Aleutian Islands (Attu Island being the westernmost) and the Commander Islands, which belong to Russia.
The westernmost U.S. island in real terms, however, is Attu Island, west of which runs the International Date Line.

180th meridian

180°antimeridianAnti-Meridian
It passes through the middle of the Pacific Ocean, roughly following the 180° line of longitude but deviating to pass around some territories and island groups.
This meridian is used as the basis for the International Date Line, but the latter deviates from it to maintain date consistency within the territories of Russia, the United States, Kiribati, Fiji and New Zealand.

Attu Island

AttuAttuanAttu Battlefield and U.S. Army and Navy Airfields on Attu
The IDL crosses between the U.S. Aleutian Islands (Attu Island being the westernmost) and the Commander Islands, which belong to Russia.
In the chain of the Aleuts, the next island to the west of Attu are the Russian Commander Islands, 208 mi away (and on the other side of the International Date Line).

Diomede Islands

Big Diomede IslandDiomede IslandGvozdev
(Wrangel Island lies directly on the meridian at 71°32′N 180°0′E, also noted as 71°32′N 180°0′W.) It then passes through the Bering Strait between the Diomede Islands at a distance of 1.5 km from each island at 168°58′37″ W. It then bends considerably west of 180°, passing west of St. Lawrence Island and St. Matthew Island.
Because they are separated by the International Date Line, Big Diomede is almost a day ahead of Little Diomede, but not completely; due to locally defined time zones, Big Diomede is only 21 hours ahead of Little Diomede (20 in summer).

American Samoa

America SamoaSamoaAS
South of Kiribati, the IDL returns westwards but remains east of 180°, passing between Samoa and American Samoa.
Its location is centered on 14.2710° S, 170.1322° W. It is east of the International Date Line, while Samoa is west of the Line.

Commander Islands

Komandorski IslandsCommanderKomandorski
The IDL crosses between the U.S. Aleutian Islands (Attu Island being the westernmost) and the Commander Islands, which belong to Russia.
Between the two runs the International Date Line.

Tuvalu

Ellice IslandsElliceEllice group
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.
It is composed of three reef islands and six true atolls spread out between the latitude of 5° to 10° south and longitude of 176° to 180°, west of the International Date Line.

Bering Strait

Bering StraitsIce CurtainBeering's Straits
(Wrangel Island lies directly on the meridian at 71°32′N 180°0′E, also noted as 71°32′N 180°0′W.) It then passes through the Bering Strait between the Diomede Islands at a distance of 1.5 km from each island at 168°58′37″ W. It then bends considerably west of 180°, passing west of St. Lawrence Island and St. Matthew Island.
The International Date Line runs equidistant between the Strait's Diomede Islands at a distance of 1.5 km, leaving the Russian and American sides usually on different calendar days, with Cape Dezhnev 21 hours ahead of the American side (20 hours during daylight saving time).

UTC−12:00

UTC−12Howland and Baker IslandsIDLW
Two US-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 latest time on Earth (UTC−12:00 hours).
It is the offset of the time zone that is the last to celebrate a New Year, sometimes referred to as the International Date Line West time zone (IDLW).

Meridian (geography)

meridianmeridiansmeridian line
The IDL is roughly based on the meridian of 180° longitude, roughly down the middle of the Pacific Ocean, and halfway around the world from the Greenwich meridian.
As there are 360 degrees in a circle, the meridian on the opposite side of the earth from Greenwich, the antimeridian, forms the other half of a circle with the one through Greenwich, and is at 180° longitude near the International Date Line (with land mass and island deviations for boundary reasons).

UTC+14:00

UTC+14Etc/GMT-14furthest east time zone
Kiribati's easternmost islands, the southern Line Islands south of Hawaii, have the most advanced time on Earth, UTC+14:00 hours. For example, at 10:15 UTC Thursday, it is 23:15 Wednesday in American Samoa (UTC−11:00), Thursday in most of the world, and 00:15 Friday in Kiritimati (UTC+14:00).
UTC+14:00 stretches as far as 30° east of the 180° longitude line and creates a large fold in the International Date Line around the Pacific nation of Kiribati.

Kiritimati

Christmas IslandKiritimati IslandKiritimati (or Christmas Island)
For example, at 10:15 UTC Thursday, it is 23:15 Wednesday in American Samoa (UTC−11:00), Thursday in most of the world, and 00:15 Friday in Kiritimati (UTC+14:00).
Despite being 2460 km east of the 180 meridian, a 1995 realignment of the International Date Line by the Republic of Kiribati moved Kiritimati to west of the dateline.

Line Islands

LineNorthern Line IslandsSouthern Line Islands
Kiribati's easternmost islands, the southern Line Islands south of Hawaii, have the most advanced time on Earth, UTC+14:00 hours. These include portions of the Republic of Kiribati, including Millennium Island in the Line Islands, as well as Samoa during the southern summer.
The International Date Line passes through the Line Islands.

Pacific Ocean

PacificSouth PacificWestern Pacific
It passes through the middle of the Pacific Ocean, roughly following the 180° line of longitude but deviating to pass around some territories and island groups.
Micronesia, which lies north of the equator and west of the International Date Line, includes the Mariana Islands in the northwest, the Caroline Islands in the center, the Marshall Islands to the east and the islands of Kiribati in the southeast.

Kiribati

Republic of KiribatiI-KiribatiGilbert Islands
The IDL circumscribes Kiribati by swinging far to the east, almost reaching the 150°W meridian. These include portions of the Republic of Kiribati, including Millennium Island in the Line Islands, as well as Samoa during the southern summer.
Their spread straddles both the equator and the 180th meridian, although the International Date Line goes round Kiribati and swings far to the east, almost reaching the 150°W meridian.

Samoa

Western SamoaIndependent State of SamoaSamoan
South of Kiribati, the IDL returns westwards but remains east of 180°, passing between Samoa and American Samoa.
At the end of December 2011, Samoa jumped forward by one day, omitting 30 December from the local calendar, when the nation moved to the west of the International Date Line.

Caroline Island

Millennium IslandCarolineCaroline Atoll
These include portions of the Republic of Kiribati, including Millennium Island in the Line Islands, as well as Samoa during the southern summer.
A 1995 realignment of the International Date Line made Caroline Island one of the first points of land on Earth to reach January 1, 2000 on the calendar.

Chatham Islands

ChathamChatham Islands CouncilChatham Archipelago
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.
The International Date Line lies to the east of the Chathams, even though the islands lie east of 180° longitude.

St. Lawrence Island

Saint Lawrence IslandSt Lawrence IslandSt. Lawrence
(Wrangel Island lies directly on the meridian at 71°32′N 180°0′E, also noted as 71°32′N 180°0′W.) It then passes through the Bering Strait between the Diomede Islands at a distance of 1.5 km from each island at 168°58′37″ W. It then bends considerably west of 180°, passing west of St. Lawrence Island and St. Matthew Island.
On June 22, 1955, during the Cold War, a US Navy P2V Neptune with a crew of 11 was attacked by two Soviet Air Forces fighter aircraft along the International Date Line in international waters over the Bering Straits, between Siberia's Kamchatka Peninsula and Alaska.

Fiji

Fiji IslandsRepublic of FijiFijian
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.
The 180° meridian runs through Taveuni but the International Date Line is bent to give uniform time (UTC+12) to all of the Fiji group.

Niue

Niue IslandNiue-FekaiNiueans
American Samoa, the Cook Islands, Niue, and French Polynesia are east of the IDL and one day behind.
Niue is separated from New Zealand by the International Date Line.

Guam

Territory of GuamGUGuamanian
The change was also applied to Mariana Islands, Guam and Caroline Islands since they also belonged to Spain.
An unofficial but frequently used territorial motto is "Where America's Day Begins", which refers to the island's proximity to the International Date Line.

Marshall Islands

MarshallsRepublic of the Marshall IslandsMarshall
Kwajalein atoll, like the rest of the Marshall Islands, passed from Spanish to German to Japanese control during the nineteenth and twentieth centuries.
The Marshall Islands, officially the Republic of the Marshall Islands (Aolepān Aorōkin M̧ajeļ), is an island country and a United States associated state near the equator in the Pacific Ocean, slightly west of the International Date Line.

Seventh-day Adventist Church in Tonga

Seventh-day Adventist Church of TongaAdventist mission in TongaSeventh Day Adventists
In Tonga, Seventh Day Adventists (who usually observe Saturday, the seventh-day Sabbath) observe Sunday due to their understanding of the International Date Line, as Tonga lies east of the 180° meridian.
Tonga lies to the east of the 180° meridian but to the west of the International Date Line (IDL), in the time zone UTC+13:00.