World Time Zones A (Not So) Simple Introduction to Time Zones
On first glance, the concept of time zones is a relatively simple one. Thanks to time zones, wherever you are in the world, the sun will rise after midnight and set after midday, with 12 noon more or less when the sun is highest in the sky.
And there's 24 hours in a day, therefore twenty-four time zones, right? Wrong!
There are actually 25 primary, or integer, time zones spanning the globe. Greenwich Mean Time sits bang in the middle, with twelve zones preceding it and twelve following, each an hour separate from its neighbours either side. That is, until you get to the two zones which straddle the international dateline. The time is the same in each of these zones, but the date is different.
Dig a little deeper and it becomes even more confusing. Not all countries and territories abide by the single hour transitions, meaning India sits 5.5 hours ahead of GMT, with Afghanistan and parts of Australia among the other areas choosing to settle on the half-hour. Some particularly uppity states have raised the stakes even higher: Nepal, for example, whose clocks tick merrily away five and three-quarter hours ahead of London.
Russia covers an incredible eleven time zones, but in China (which geographically covers five time zones), the time is always the same, regardless of where in the country you are. Take a single step across the border from Afghanistan into China and you'd need to move your watch on some three and a half hours.
Even more perplexing, visit the Line Islands in the central Pacific ocean and you'll be 14 hours ahead of GMT, meaning 26th December starts for them while it's still Christmas Eve in some parts of the world.
Confused yet? Quite probably, but still not as confused as I was sitting in the offices of a London travel agency a while back. As I surveyed the bank of destination clocks facing me I was shocked to find them claiming that when it was midday in London, it was 6.17am in New York and 3.40pm in Moscow. In an instant I knew exactly what time it was: It was time for them to invest in some new clocks!
