Date line and GMT?

Question

I am very confused. I thought the time starts at the international dateline between New Zealand and and Alaska. Therfore Australia and New Zealand would be ahead of Europe and the USA in time.

So whats the Greenwhich mean time business? If Greewhich has the 0 degree Meridian why doesnt the time start there?

Answer 1

Opposite sides of the world. You start counting at Greenwich. If two people go in opposite directions, they will meet up again at the international dateline.

Answer 2

Time doesn't start at any one point. Time is a continuum, that is it has no beginning and no end. The measuring of time is a human construct. Animals don't have a concept of time as far as we know. Only humans feel the need to measure the passage of time.

Using Greenwich as the 0 point in referencing longitude gives everyone a point to start. The International Dateline is opposite the Greenwich meridian, another convention to allow for uniformity. The dateline zig-zags to accommodate the island groups that are near 180 degrees West.

Currently UT or UTC counts midnight as the end of one day and the beginning of another. Since humans tend to be more active during daylight, it makes sense to change from one day to the next when most are inactive and least affected. Think of the confusion that would result if each day you went to work at 8 am (daylight) and changed from Monday to Tuesday 4 hours later.

Answer 3

Greenwhich Mean Time is the standard set by Great Britain to co-ordinate its vast empire. The International Dateline is not 100% along the 180 degree meridian, but zig-zags to accommodate island chains for ease of everybody along the line.

So why does the day start at midnight in the middle of nowhere? Well people just agreed that midnight would start the new day and western world powers (European countries and the USA) wanted to stay as much on the same day as possible.

Before the rise in rapid communication (telegraph) and the railroads, people were just content to use local time (high noon) according to their sundials to set their clocks.

Answer 4

the Greenwich meridian starts the time because the greenwich meridian is either on the international date line or is the international date line. New zealand is the first country in time followed by Australia. Europe countries like England is 8.5 hours behind Australia and the USA is 1 day behind Australia.

Answer 5

They're just 180 degrees apart. Greenwich Mean Time was a base starting point to coordinate the activity of the vast global British Empire. One the other side of the world is the IDL where the day begins. It is convenient because it starts in an empty expanse of the Pacific Ocean. Just about any other place on the globe it would run through a large population area.

I just crossed the IDL flying from GUAM to Hawaii. I left Sunday morning the 29th of April and landed Saturday evening the 28th!

Answer 6

UTC [Universal Time Code] = Zulu Time = GMT
All times zones are relative to what time it is at the Greenwich Observatory. I guess this has something to do with fact that at one point in history England had colonies all around the world [the whole "the Sun never sets on the British Empire" saying] and they needed a standardized time reference in order to help establish whatever longitude lcolonies/ships were at. It kinda stuck that we still use Greenwich as the starting point even though the world time is measured/tracked/timed by the US Naval Observatory's atomic clocks [see http://tycho.usno.navy.mil for more info].