wer (see Figure 1-1) or the clock at the local church as a time reference for the surrounding com- munity. Time was announced to villagers by bells, commonly on the quarter hour (one chime for each quarter), and then a much deeper set of "bongs" on the hour-one for each hour from 1-12. Figure 1-1 Zytturm (Clock Tower) in Zug, Switzerland Therefore, every community had its own local version of time, as proclaimed to all the people within earshot of the bells. However, the clocks in neighboring villages could be significantly dif- ferent from each other, and there was no easy means to synchronize them. Commonly, the position of the sun was used as the basis for a timepiece (the sundial); however, this meant that every location had its own "local" version of time (since, at any one time, the sun is in a different position in the sky for every place on the earth). The position of the sun at specific times, such as noon (when the sun is highest in the sky), was used to help set the time on the local com- munity clock. But since noon is quite dependent on position (particularly longitude), the clocks across a country would vary quite significantly (moving from west to east, the clocks would show the time to be increasingly later and later). With the arrival of faster transport like railways, this situation became untenable, as every station on the railway line needed to agree on a common time SO that standardized timetables would become meaningful. It was this need which led to the adoption of standardized times and eventually to Greenwich Mean Time (GMT) and the system of time zones used today. With the arrival of more accurate mechanical timepieces and particularly communications via the telegraph, the ability to synchronize clocks across a wider area also became possible. GMT was established in 1884 at the International Meridian Conference held in Washington, DC, where the meridian passing through Greenwich (near London) was adopted as the initial or prime meridian for longitude and timekeeping. Given that there are