Time zones are geographical areas that have one particular thing in common: their time. Due to the fact that the earth circles the sun, causing day and night, it can’t be the same time all over the world at the exact same moment. Time moves forward, just as the earth moves. Time zones are areas that were created as a way to adjust the time in different parts of the world as the earth goes through its orbit. It could be 8pm in one part of the world and already the next day at noon in another part of the world.
What are Time Zones'
Time zones are areas that, theoretically, are 15 degrees of longitude wide. However, many zones vary in distance, as countries try to stay within a certain number of time zones or want particular areas to stay within the same time zone. When discussing time zones, there are two main lines of longitude that are referenced: the Greenwich Meridian and the International Date Line. The Greenwich Meridian is considered 'zero' longitude, and that is where all time zones begin and end. That line is in the city of Greenwich, in the United Kingdom. The International Date Line is 180 degrees away from the Greenwich Meridian, or exactly halfway around the world. It is exactly one day later at the International Date Line. All areas in between these two locations are divided into areas of hours before and after those times.
On a side note, Daylight Savings Time comes into play in many countries. That is where the time in a particular zone will change by one hour to allow more sunlight during the usual waking hours.
What Is Longitude and How Does It Fit In'
Any area in the world, any location, any point on a map, can be identified by using two reference points: longitude and latitude. They are referred to as “coordinates” on a map grid. Lines of latitude run parallel to the equator, beginning at the equator and going up and down from that point. Lines of longitude begin at the Greenwich Prime Meridian and travel each way from that point, parallel to the prime meridian and perpendicular to the equator. Times zones are established with lines of longitude. The prime meridian is zero degrees longitude, and the International Date Line, halfway around the world, is approximately 180 degrees longitude. All time zones in between are created based on the number of lines of longitude between each point.
How Were Time Zones Created'
At one time there were no time zones. People kept track of time by using the position of the sun in the sky. In more primitive days, a sundial was used to determine the time. But even as technology progressed, it still wasn’t necessary for time to be an exact science. That changed with the development of the railroad. Due to the fact that railroads had to pick passengers and cargo up in one city, and then deliver them to another city, standards had to be reached for the sake of a schedule. On November 18, 1883, both the United States and Canada established a set of time zones. The idea didn’t take for a while, and some cities still had “local” time and “railroad” time, but as technology and industry progressed even further, the standards began to take shape.
What is the Difference Between Universal Time and Greenwich Time'
Greenwich Mean Time is a time-keeping method developed with the Greenwich Observatory in the United Kingdom. Time was “kept” by observing the movement of the sun through the observatory. The sun does not always move at the same rate during different times of the year, so this was an estimated rate, rather than one that was “set in stone.” The term “universal time” was adopted in 1928 by the International Astronomical Union, and it refers simply to the time that had, until then, been referred to as Greenwich Mean Time. In other words, it became a universal and standard method by which to judge time. Today, with sophisticated instruments, such as computers and satellites, we use what is known as Coordinated Universal Time, abbreviated “UTC.” This is the new and accepted standard of time, and all time zones are based on this time.
Can I Calculate the Time in Another Part of the World'
It is difficult to determine exactly the time zone of a different part of the world. If each time zone was, indeed, divided into sections of 15 degrees longitude, one could count them out across a globe or atlas to determine the number of hours the area differed from the spot where one was standing. However, as mentioned before, some countries have set out their own time zones, and they vary slightly, or significantly, from 15 degrees. There are some guidelines, however, that may assist one if they would like to count out and determine scientifically the time in another country.
Please Provide Me With Some Time Zone Maps and Easy Conversions
For those who seek an easier solution, there are many conversion charts and cheat sheets on the Internet. One can access world clocks that will keep time in all main cities or areas of the world. There are world maps and atlases that delineate the actual time zones, complete with hour differences. There area a number of sites available for these time conversions.
Time Zones (PDF)
What is the International Meridian Conference'
In the 1880s the United States Congress urged President Chester Arthur to determine the desirability of a more accurate standard of time, based on geographic and marine positions. President Arthur saw the interest from other countries, and he created the International Meridian Conference in 1884 to set up these standards. Twenty-five nations were represented, and forty-one people attended. The Conference set many important standards, such as adoption of a single world meridian and a “universal day” (beginning at midnight in Greenwich).