Most of the world uses the 24-hour clock, also known as military time. This clock is based on the 12-hour clock, but with each hour represented by a number from 0-23. The 12-hour clock is based on the 360-degree circle, with each hour represented by a 15-degree wedge.
The first time zone, Greenwich Mean Time, was established in 1884. GMT is calculated by taking the mean time of the sun at the Royal Observatory in Greenwich, England. This time zone…