Question

what is interational date line? what is it significance​

Answer 1

Answer:

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The International Date Line serves as the "line of demarcation" between two consecutive calendar dates. ... The International Date Line, established in 1884, passes through the mid-Pacific Ocean and roughly follows a 180 degrees longitude north-south line on the Earth.

Significance of International Date line

It describes the border from one day to the next.

Though the times on either side of the line are close to each other, the date on the west side is a day ahead of the date on the east side.

Answer 2

Answer and Explanation:

International Date Line, also called Date Line, imaginary line extending between the North Pole and the South Pole and arbitrarily demarcating each calendar day from the next. It corresponds along most of its length to the 180th meridian of longitude but deviates eastward through the Bering Strait to avoid dividing Siberia and then deviates westward to include the Aleutian Islands with Alaska. South of the Equator, another eastward deviation allows certain island groups to have the same day as New Zealand.  

The International Date Line is a consequence of the worldwide use of timekeeping systems arranged so that local noon corresponds approximately to the time at which the sun crosses the local meridian of longitude (see Standard Time). A traveler going completely around the world while carrying a clock that he advanced or set back by one hour whenever he entered a new time zone and a calendar that he advanced by one day whenever his clock indicated midnight would find on returning to his starting point that the date according to his own experience was different by one day from that kept by persons who had remained at the starting point. The International Date Line provides a standard means of making the needed readjustment: travelers moving eastward across the line set their calendars back one day, and those traveling westward set theirs a day ahead.