Pacific Time Zone

The Pacific Time Zone observes standard time by subtracting eight hours from Coordinated Universal Time (UTC−8). The standard time in this zone is based on the mean solar time of the 120th meridian west of the Greenwich Observatory. During daylight saving time, its time offset is UTC−7 and is thus based on the mean solar time of the 105th meridian west of the Greenwich Observatory.

In the United States and Canada, this time zone is generically called the Pacific Time Zone (PT). Specifically, it uses Pacific Standard Time (PST) when observing standard time (late autumn to early spring), and Pacific Daylight Time (PDT) when observing daylight saving time (early spring to late autumn). Most of Canada uses daylight saving time. In Mexico the UTC−8 time zone is known as the Northwest Zone, which is synchronized with the U.S. PDT daylight saving schedule.

The largest city in the Pacific Time Zone is Los Angeles, California; the city's metropolitan area is the largest in the zone.

Time zone

A time zone is a region that observes a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions because it is convenient for areas in close commercial or other communication to keep the same time.

Most of the time zones on land are offset from Coordinated Universal Time (UTC) by a whole number of hours (UTC−12 to UTC+14), but a few are offset by 30 or 45 minutes (for example Newfoundland Standard Time is UTC−03:30, Nepal Standard Time is UTC+05:45, and Indian Standard Time is UTC+05:30). Some higher latitude countries use daylight saving time for part of the year, typically by changing clocks by an hour. Many land time zones are skewed toward the west of the corresponding nautical time zones. This also creates a permanent daylight saving time effect.

History

Early timekeeping

Before clocks were first invented, it was common practice to mark the time of day with apparent solar time (also called "true" solar time) – for example, the time on a sundial – which was typically different for every settlement.

Central Time

Central Time may refer to:

New York

New York is a state in the Northeastern United States and is the United States' 27th-most extensive, fourth-most populous, and seventh-most densely populated state. New York is bordered by New Jersey and Pennsylvania to the south and Connecticut, Massachusetts, and Vermont to the east. The state has a maritime border in the Atlantic Ocean with Rhode Island, east of Long Island, as well as an international border with the Canadian provinces of Quebec to the north and Ontario to the west and north. The state of New York, with an estimated 19.8 million residents in 2015, is often referred to as New York State to distinguish it from New York City, the state's most populous city and its economic hub.

With an estimated population of nearly 8.5 million in 2014, New York City is the most populous city in the United States and the premier gateway for legal immigration to the United States. The New York City Metropolitan Area is one of the most populous urban agglomerations in the world. New York City is a global city, exerting a significant impact upon commerce, finance, media, art, fashion, research, technology, education, and entertainment, its fast pace defining the term New York minute. The home of the United Nations Headquarters, New York City is an important center for international diplomacy and has been described as the cultural and financial capital of the world, as well as the world's most economically powerful city. New York City makes up over 40% of the population of New York State. Two-thirds of the state's population lives in the New York City Metropolitan Area, and nearly 40% live on Long Island. Both the state and New York City were named for the 17th century Duke of York, future King James II of England. The next four most populous cities in the state are Buffalo, Rochester, Yonkers, and Syracuse, while the state capital is Albany.

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south and is bounded by Asia and Australia in the west and the Americas in the east.

At 165.25 million square kilometers (63.8 million square miles) in area, this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of the Earth's water surface and about one-third of its total surface area, making it larger than all of the Earth's land area combined.

The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific. The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres (35,797 ft).

The eastern Pacific Ocean was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great "southern sea" which he named Mar del Sur. The ocean's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacifico, which in both Portuguese and Spanish means "peaceful sea".