Time Travel

The population of a small island in the South Pacific Ocean have perfected time travel! The island of Samoa is planning a jump into the future by moving themselves west of the International Date Line. Perhaps the island's population have grown tired of being some of the last people on earth to celebrate the New Year? Jokes aside, the real reason relates to the economy. Currently Samoa loses two working days with it's biggest trading partners - New Zealand and Australia. Currently when it's Friday in New Zealand its Saturday in Samoa, and when it's Sunday in Samoa, it's Monday in New Zealand.

The International Date Line (IDL) is an imaginary line that runs generally north-south through the middle of the Pacific Ocean. It's function is to define the position on the Earth's surface where the date changes. Traveling east across the line means you repeat a day, while crossing it in a westerly direction means you jump forward a day!

The line follows the 180 degree meridian for the most part except where it goes around parts of continents or islands (no avoid a single nation have time zones in 2 different days). Samoa, lies just east of the line, and so the change in position will only lead to a small additional kink in the line on the new maps.

If you extend the IDL into the other hemisphere, the line is called the Prime Meridian or perhaps better known as the Greenwich meridian as it passes through the Royal Observatory in Greenwich in southeast London. This arbitrary line was agreed to as the zero position of longitude at the International Meridian Conference held in 1884. The same conference defined the "Universal Day" as midnight-to-midnight Greenwich Mean Time (GMT), but decided that countries could unilaterally decide how to measure time. It is for this reason that some countries like India choose to have 1 time zone that is 05h30 ahead of GMT!

What time is it?

This artificial line creates the Eastern and Western Hemispheres also creates some interesting time phenomena (although they are completely artificial constructs). For example, you can celebrate your birthday twice in one year by crossing the IDL in a easterly direction on your birthday. The clocks go back a day and you get to celebrate again!

Another strange phenomenon is that for 2 hours each day (between 10h00 and 11h59 GMT) three different days are observed in different places on the globe. At 10h30 in Greenwich it's Tuesday, while in Samoa it's 23h30 on Monday night, and across the IDL in Kiritimati or Christmas Island it's Friday morning 00h30!  

Samoa has a population of about 180,000. I suppose they will enjoy being one of the first nation's to experience the New Year at 00h01 on January 2012!