how time zones started

Once people began to travel quickly over large distances (by train for example), getting the right time at the destination, and all places on the way, became very important.

Imagine trying to set up a train timetable when all places on the route have slightly different times!

This is a picture of Sir Sanford Fleming who, in 1878, came up with a great idea for organizing time in different places. He suggesting that the world should be divided into 24 time zones, one for each hour in a day. All places within each zone would use exactly the same time

But where should time start on the Earth? Since there are 360^o in a circle, each of Fleming’s 24 time zones is equivalent to 15^o of longitude so the question is the same as asking where the measurement of longitude should start.

Fleming's 15-degree time-zone wedges were an excellent solution to the worldwide time chaos!

Take a look at this view of the Earth (from the South pole) You can see 24 ‘15 degree’ wedges

Here’s a picture (thanks to Joe Mehaffey) of the metal bar in the path at Greenwich that marks the prime meridian (zero longitude). Joe has one foot in the western hemisphere and one in the eastern hemisphere!

An international conference of delegates from 25 countries was held in Washington DC, USA in 1884 to decide where point zero in longitude should be. Greenwich in England was chosen as the place for the Prime Meridian - the zero degree starting position for longitude. It was also decided that the first time zone in Fleming’s system should be centred on Greenwich too. This was the start of Greenwich Mean Time (GMT) which is now officially called Universal Time (UT)