Longitude is an imaginary line running from the North Pole to the South through Pole. The Prime Meridian, which passes Greenwich, England, is longitude 0° It sets the world standard time and divides the world into the Eastern Hemisphere and the Wester Hemisphere. From the Prime Meridian at 0° to the range of longitudes is from 0° to 180° West, and from the prime meridian at 0° to the east the range of longitudes is from 0° to 180° East