PHYSICAL CHARACTERISTICS OF TIME ZONES

With the exceptions of zones MIKE and YANKEE, which we will discuss later, each time zone spans 15 of longitude, with the 24 principal meridians bisecting (dividing in half) each zone. At the equator, each degree of longitude spans 60 nautical miles (NMs). Thus, a time zone spans 900 NMs (15 x 60 = 900).

NOTE: Remember, only at the equator is each degree of longitude equal to 60 NMs. The natural curvature of the earth causes a narrowing of the zones as the north or south latitude increases. The length of a degree of longitude gets progressively smaller the farther it is from the equator.

Time zones generally correspond with the principal meridians; however, sometimes they deviate from their geographical meridians, especially on land areas. This is common along coastlines, in mountain ranges, and along country borders. These deviations keep time constant wherever possible throughout countries, states, cities, and island chains. See figure 1-1.

Privacy Statement - Press Release - Copyright Information. - Contact Us - Support Integrated Publishing