International Time zones, World Clock

The History of Time Zones

As trade among countries expanded with the invention of the railroads, a more universal way of determining world time became more necessary. In the late 1870s Sanford Fleming, a Canadian engineer, devised a plan to end the confusion of determining world time between countries worldwide.

World Time

Our natural concept of time is linked to the rotation of the earth and we define the length of the day as the 24 hours it takes (on average) the earth to spin once on its axis. As time pieces became more accurate and communication became global, there needed to be a point from which all other world times were based.

International Time Zones

Since Great Britain was the world's foremost maritime power when the concept of latitude and longitude came to be, the starting point for designating longitude was the "prime meridian". The "starting" point for calculating the different time zones was agreed to be the Royal Greenwich Observatory,UK, which is zero degrees. The longtitudes are calculated East (+GMT) and West(-GMT) to determine the time zone maps for all countries.

International Time

Unfortunately the Earth does not rotate at exactly a constant rate. Due to various scientific reasons and increased accuracy in measuring the earth's rotation, a new timescale, called Coordinated Universal Time (UTC), has been adopted and replaces the term GMT. The Navy, as well as civil aviation, uses the letter "Z" (phonetically "Zulu") to refer to international time at the prime meridian. So when you hear "Zulu Time", it is known as Greenwich Mean Time (GMT).

In 1884, 27 nations met in Washington, D.C. for a conference that is today is called the International Meridian Conference. During the conference, the representatives agreed on the international time zones and the time zone maps that we use today. They also agreed that the day would start at midnight. These steps became the basis for world time, a world time clock, and a world map comprised of international time zones. While a China and India have only 1 time zones countrywide, Russia has 11 different time zones. The North American Time Zones are divided into 7 times zones.
  • Newfoundland time zone
  • Atlantic time zone
  • Eastern time zone
  • Central time zone
  • Mountain time zone
  • Pacific time zone
  • Alaska time zone
The Canadian Time Zones have six time zones and the American Time Zones have all seven different usa time zones. The United States time zones also observe Daylight Savings Time from March to Nov. Mexico which has 3 time zones, observes Daylight Savings Time from May to September.

World Clock

As communication is more immediate with the use of better telephone reception and the internet, contacting people worldwide has become more important. Our International Planners and Calendars contain USA Time Zone Maps, World Time Zone Maps, and an easy-to-use time zone converter for making international communication easier.