Anybody knows the funda behind the international date line?

Question

I have heard that the date changes when you cross the international date line. On one side of the line its sunday and on the other its saturday. howcome? what if you stand on the line? Which day would it be?

Answer 1

Most of the time the Earth has two dates. Where there is midnight the next day has started. That is one boundary to this date. You can't have two dates with just one dividing line. Beside midnight, the date line is the other dividing line. You could have one foot in Saturday and one foot in Sunday.

Answer 2

Those pesky, yet clever English. They set up the Greenwich Prime Meridian to go right through London. Then they divide up the world into 24 main lines of longitude, for each hour of the day. They do this because they are the masters of the ocean even back in the 17th century. Well if I set sail (or fly) from England at noon Saturday and sail west fast enough, the sun would always be at noon and my clock would reset to 12 noon at every time zone change. So if I sailed (or flew) around the world west bound, I would arrive back in London 24 hours later and my chronometer would say Saturday 12 noon, but in London it would be Sunday noon. OH NO!
So they had to choose a line of longitude, or meridian, to not let time run away like this. And why not the middle of the Pacific, far away from London. So that is how it came to be. The old statment Sunday San Francisco, Monday Manila. Of necessity, the line zigzags to keep countries within the same day. And the mighty nation of Kiribati decreed in 1995 the line move for its own purposes. You could have New Years Eve in New Zealand, hop a flight East to Honolulu, and celebrate New Year again!