Today started as my birthday. A delightful day spent in a tin tube at 40,000 feet travelling more or less due south at just over 500mph. The day finished just 15 hours later, leaving me with a truncated birthday. The reason? the international date line ….
The international date line is an imaginary line roughly based on the meridian of 180° longitude. It goes roughly down the middle of the Pacific Ocean, and halfway around the world from the Greenwich meridian. In many places, it follows the 180° meridian exactly. In other places, however, the IDL deviates east or west away from that meridian. Generally this is for economic or political reasons. For example, on December 29th 2011 Samoa (and their neighbours Tokelau) decided arbitrarily to jump one day. So they lost the whole of December 30th and in one fell swoop became the very first place on the globe to bring in the New Year. Allegedly the move was to bring them into line with their Asian-Pacific trading partners, but it seems more likely that they just want to be the first to party …..
One of the biggest zigzags goes around Kiribati. Kiribati is made up of 32 atolls that straddle the equator. In 1995 they moved a chunk of the line to the east so that the entire country was on the same side. Presumably less confusing all round – particularly when it comes to inter-island ferry timetables!
