Why are there Different Time Zones?

Answering this question is really rather easy. Human beings live their everyday lives by the clock so they established time zones to fit with the daylight available during their waking hours. If not for the various time zones around the globe there would be some countries in which 12 noon would come at the darkest time in a 24-hour period. Another problem would arise when nation’s tried to decide who would be privileged to have the middle of the day occur when the sun is at its highest point.

Of course, to have accurate and usable time zones around the planet there has to be a starting point. This must be a location on which nearly everyone can agree. We currently measure our time of day from a place in the United Kingdom known as Greenwich. The meridian that passes through this point is the zero point for establishing time in the rest of the world. (Lines of longitude run from one pole to another and establish location as we travel east or west around the world.)

To figure out what time it is in another part of the world we need to know how far from Greenwich we are. For example, a point in the United States that is five time zones “west” of Greenwich would have a time five hours earlier in the day. The sun comes to Greenwich from the “east” and arrives there five hours sooner than the spot in the United States.

Each time zone is roughly equal to 15 degrees of longitude, with the entire globe comprised of 360 degrees. The standard size of the time zone was set in the 1800s and continues to govern our time settings today. Twenty-four zones were established and the physical location is the same. However, the buildings that once made up the observatory at Greenwich aren’t there now. The facility is now at Sussex, though time is still measured from the original Greenwich meridian.

Time zones may be even more important in the 21st century as populations around the world communicate almost instantly through the Internet and satellite phones. According to various histories and encyclopaedia information, Greenwich Mean Time was set in 1675 with the construction of the Royal Observatory. But fine tuning of times around the world didn’t occur until the first time zone was established in 1847.

By 1868 the country of New Zealand adopted a standard time based on Greenwich. The new standards created by time zones helped many businesses, including U.S. railroad. Prior to adopting standard times based on these zones, the railroad companies used their own “standard” times. A standard time zone was set in Washington D.C. a few years later.

Most nations had adopted their time zones by the late 1920s. But some countries have established times that differ by half an hour from what would be the standard time in that location. Except for adjustments for daylight saving time in some places, the established time zones control our clocks today.