International date lin

What Happens When You Cross the Dateline?

The international date line is an imaginary line that separates one day from another on the globe, but it's not a perfectly straight line. 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 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.

The International Date Line sits on the º line of longitude in the middle of the Pacific Ocean, and is the imaginary line that separates two consecutive calendar​. The International Date Line (IDL) is an imaginary line on Earth's surface defining the boundary between one day and the next.​ The International Date Line is located halfway around the world from the prime meridian (0° longitude) or about ° east (or west) of Greenwich, London. More than a century after its creation, world wars, and the emergence of a ​hour information culture, the International Date Line is still a.

The international date line is an imaginary line that separates one day from another on the globe, but it's not a perfectly straight line. 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 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.






Match the time bar color to the map color at the bottom. It international not a perfectly straight line and has been moved slightly over the years to accommodate needs or requests date varied countries in the Pacific Ocean. Lin to the left international the International Date Line, the date is always one international ahead of the date or day immediately to the right of the International Date Lin in the Western Hemisphere. On the time and date codes shown below, note lin Tonga and American Samoa have the same time lin are one lin apart, as American Samoa is in the Western Hemisphere, on the date side datf the Inteernational Dateline from Tonga.

As you travel further west, note that the time in Fiji is one hour earlier than Tonga. You international also notice that Hawaii, date to the east of American Samoa, is one hour later in time. Date, travel east across the International Date Line results in a day, or 24 hours, being subtracted.

Travel west across the International Date Line results in a international being added. Mozilla Date, still display it as GMT. The UTC Time shown directly below is the standard time zone upon which all other worldwide time zones are based.

It never observes daylight saving time. Match the time bar color to the map color at the bottom Print this map View time zone clocks.

So, travel east across the International Date Line results in a day, or 24 hours, being subtracted. Travel west across the International Date Line results in a day being added. Mozilla Firefox, still display it as GMT. The UTC Time shown directly below is the standard time zone upon which all other worldwide time zones are based. People relied on the definition that "noon" was when the sun was highest in the sky, and due south. One "day" was simply the amount of time between two consecutive "noons.

The problem was, each city experienced noon at its own apparent p. Depending on longitude, adjacent cities could have a time of, say, a. Near the equator, traveling westward by about 1, miles 1, kilometers delays the arrival of noon by one hour.

In the 19th century, the emergence of transcontinental railroads further complicated matters. That century also saw accurate mechanical timepieces becoming widely available. Travelers found themselves resetting their watches by several minutes at every station to the east or west. This was inconvenient at best.

Also in that century, the emergence of telegraphy created time-keeping issues for commercial and military entities — the early adopters. The telegraph, invented in by Pavel Schilling, was the first true "instant messaging" IM system. It allowed communication over great distances using electricity, which moves nearly at the speed of light.

And of course, to use either system effectively, it's helpful to know the clock times at both the sender's and receiver's locations. Before we explain how time zones solved these clock problems, let's do a quick review of latitude and longitude.

Around B. It was a coordinate system for locating points on the surface of a sphere. The vertical axis measured "latitude," and the horizontal axis "longitude.

During the Age of Discovery, beginning in the 15th century, cartographers saw the need for standardized latitude and longitude measurement. If your intent is to map or claim a geographic location, you need to describe its position unambiguously. Britain "ruled the waves" at the time, and took the early lead in this endeavor. Portugal and Spain, the other major seafaring nations, were using their own systems, but eventually deferred to England.

Latitude was less an issue than longitude, since there was no dispute about where the poles latitude 90 degrees north and 90 degrees south and equator latitude 0 degrees were located. However, the selection of a starting point for longitude measurement the 0-degree meridian was arbitrary.

It was based more on national pride and convenience. In , England designated the Prime Meridian 0 degrees longitude as the meridian running through Greenwich Observatory.

They were the dominant seafaring nation in that era, had colonies around the globe, were using state-of-the-art mechanical clocks, and were scientifically qualified to establish a standard.

You've heard the saying "The sun never sets on the British Empire. England had colonies all around the globe, so it was always "daytime" somewhere in the British Empire. Britain had clout. By the latter part of the 19th century, scientists, railroads and other emerging industries felt the need for a global standard of time. The first such system, using 24 standard time zones, was proposed by Sir Sandford Fleming in Sandford was a Scottish engineer, who helped design the Canadian railway network.

His system wasn't officially sanctioned by any global entity, but by it spawned the adoption of the time zone system in use today. Nation by nation, the world bought into Fleming's idea. Within each time zone, all clocks would be set to an average time that best represented where the sun was located in the sky. That time is called mean solar time. Sundials, by comparison, measure apparent solar time , sometimes called true solar time.

The time-zone process began in for the United States, when the nation was divided into four standard time zones. Each zone was centered on a meridian of longitude:. The United Kingdom had already started a similar process, and the rest of the world soon followed suit. By , the global system of time zones we use today was fairly well established.

Increasing global connectivity demanded some universal system of time measurement, and standard time zones were the answer. Most time zones do not precisely follow meridians of longitude. They zig and zag as needed to keep islands, smaller countries and large metropolitan areas on the same clock time — an obvious concession to convenience. Standard time zones are 15 degrees wide, since degrees divided by 24 hours equals 15 degrees per hour.

They are numbered by hour starting from the Prime Meridian longitude 0degrees , which runs through Greenwich, England. The numbering system makes it easy to find the time in other zones.

When atomic clocks were invented in the s, it became possible to measure time with an accuracy better than that provided by the rotating Earth. GMT was an "average time" system based on telescopic observations from Greenwich Observatory. Once in a while a "leap second" is added to or subtracted from the world's clock — that's a correction between GMT and UTC.

Earth's rotation period can vary from exactly 24 hours by a fraction of a second either way, depending on geologic perturbations. For example, as glaciers melt, there's a transfer of mass from higher latitudes toward the equator.

As with a figure skater who slows his spin rate by extending an arm or leg, the law of conservation of angular momentum requires a reduction of the spin rate to compensate for this redistribution of mass. Scientists estimate a magnitude 9. Astronomers must also consider the difference between apparent and mean time. Earth is divided into imaginary lines called meridians that run from the north to the south pole. In total, there are meridians of longitudes and parallels of latitudes.

With the help of these girds, the longitude and latitudes are divided into degrees and time to find an exact location. To be precise, there are 60 minutes in one degree and each degree has a distance of 69 miles. Each minute is divided into 60 seconds. As we go towards east from the International Date Line, we are reducing one day from our prior location in the west. In short, every location falling on the east of this line is one day earlier in time if compared to the locations in the west.

The distance between the degrees of latitude is somewhat same. However, the earth is slightly elliptical in shape which creates minute variations between the degrees as we go from the equator to the north and south poles.

The distance is