The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST) by subtracting ten hours from Coordinated Universal Time (UTC−10:00). The clock time in this zone is based on the mean solar time of the 150th meridian west of the Greenwich Observatory.
The zone takes its name from the two areas it includes: Hawaii and the portion of Alaska's Aleutian Islands west of 169° 30′ W longitude.
The Islands of Four Mountains (Russian: Четырёхсопочные острова) 52°52′33″N 169°47′42″W / 52.87583°N 169.79500°W is an island grouping of the Aleutian Islands in Alaska, United States. The chain includes, from west to east, Amukta, Chagulak, Yunaska, Herbert, Carlisle, Chuginadak, Uliaga, and Kagamil islands. This island chain is located between Amukta Pass and the Andreanof Islands to the west, and Samalga Pass and the Fox Islands to the east. These islands have a total land area of 210.656 sq mi (545.596 km) and have no permanent population. The two largest islands are Yunaska and Chuginadak. Chuginadak is mainly made up of the active volcano Mount Cleveland.
The name is translated from Russian Четырехсопочные Острова (Ostrova Chetyre Soposhnye) meaning "Islands of Four Volcanoes" (Sarichev, 1826, map 3). The early Russian explorers named the islands by this term because of four prominent volcanoes, each located on a separate island. The Aleut name Unigun (Uniiĝun in the modern Aleut orthography) was reported in 1940 by Father Veniaminov. There appears to be confusion regarding the names of these islands, possibly because only four of the five are on most early maps and charts. The present names were gathered in 1894 by a field party from USS Concord and published in 1895 by the U.S. Navy Hydrography Office (Chart 8).This is the first island in the Aleutian time zone, 1 hour behind Alaska with daylight saving time as of 2010.
A calendar date is a reference to a particular day, represented within a calendar system, enabling a specific day to be unambiguously identified. Simple math can be performed between dates; commonly, the number of days between two dates may be calculated, e.g., "25 December 2025" is ten days after "15 December 2025". The date of a particular event depends on the time zone used to record it. For example, the air attack on Pearl Harbor that began at 7:48 a.m. local Hawaiian time (HST) on 7 December 1941 is recorded equally as having happened on 8 December at 3:18 a.m. Japan Standard Time (JST).
A particular day may be assigned a different nominal date according to the calendar used. The de facto standard for recording dates worldwide is the Gregorian calendar, the world's most widely used civil calendar. Many cultures use religious calendars such as the Gregorian (Western Christendom, AD), the Julian calendar (Eastern Christendom, AD), Hebrew calendar (Judaism, AM), the Hijri calendars (Islam, AH), or any other of the many calendars used around the world. Regnal calendars (that record a date in terms of years since the beginning of the monarch's reign) are also used in some places, for particular purposes.
Midway Atoll (colloquial: Midway Islands; Hawaiian: Kuaihelani, lit. 'the backbone of heaven'; Pihemanu, 'the loud din of birds') is a 2.4 sq mi (6.2 km) atoll in the North Pacific Ocean. Midway Atoll is an insular area of the United States and is an unorganized and unincorporated territory. The largest island is Sand Island, which has housing and an airstrip. Immediately east of Sand Island, across the narrow Brooks Channel, is Eastern Island, which is uninhabited and no longer has any facilities. Forming a rough, incomplete circle around the two main islands and creating Midway Lagoon is Spit Island, a narrow reef.
Roughly equidistant between North America and Asia, Midway is the only island in the Hawaiian Archipelago that is not part of the state of Hawaii. Unlike the other Hawaiian islands, Midway observes Samoa Time (UTC−11:00, i.e., eleven hours behind Coordinated Universal Time), which is one hour behind the time in the Hawaii–Aleutian Time Zone used in Hawaii. For statistical purposes, Midway is grouped as one of the United States Minor Outlying Islands. The Midway Atoll National Wildlife Refuge, encompassing 590,991.50 acres (239,165.77 ha) of land and water in the surrounding area, is administered by the United States Fish and Wildlife Service (FWS). The refuge and surrounding area are part of the larger Papahānaumokuākea Marine National Monument.
The solar eclipse of August 21, 2017, dubbed the "Great American Eclipse" by some media, was a total solar eclipse visible within a band that spanned the contiguous United States from the Pacific to the Atlantic coasts. It was also visible as a partial solar eclipse from as far north as Nunavut in northern Canada to as far south as northern South America. In northwestern Europe and Africa, it was partially visible in the late evening. In northeastern Asia, it was partially visible at sunrise.
Prior to this event, no solar eclipse had been visible across the entirety of the United States since June 8, 1918; not since the February 1979 eclipse had a total eclipse been visible from anywhere in the mainland United States. The path of totality touched 14 states, and the rest of the U.S. had a partial eclipse. The area of the path of totality was about 16 percent of the area of the United States, with most of this area over the ocean, not land. The event's shadow began to cover land on the Oregon coast as a partial eclipse at 4:05 p.m. UTC (9:05 a.m. PDT), with the total eclipse beginning there at 5:16 p.m. UTC (10:16 a.m. PDT); the total eclipse's land coverage ended along the South Carolina coast at about 6:44 p.m. UTC (2:44 p.m. EDT). Visibility as a partial eclipse in Honolulu, Hawaii began with sunrise at 4:20 p.m. UTC (6:20 a.m. HST) and ended by 5:25 p.m. UTC (7:25 a.m. HST).