Time Difference, Current Local Time and Date of the World's Time Zones

What is a time zone?

A time zone is a geographical area that has the same state-regulated time, known as "standard time".

Due to the size of some countries and the spread of other places belonging under their jurisdiction, one country can be divided into a number of time zones. The United States, for example, contain twenty-nine time zones.

Why do we have time zones?

The use of time zones makes it easier for us to organise our lives, from commercial operations up to traveling. People living within the same time zone know that they will be working at the same time, while someone in another time zone will work based on the local time of his or her own time zone.

The history of time zones

Time has traditionally been measured according to the position of the sun in the sky, which is different depending on where you are in the world. In the nineteenth century, when mechanical clocks began to become popular, time was calculated locally. Since the time calculations were based on the position of the sun, they could vary by four minutes for each degree of longitude. A better system was required to enable an efficient operation of railways and new telecommunication systems.

In 1847, British railway companies began to standardize the time they were using by providing their staff with portable chronometers, resulting in what became known as ‘Railway Time’. However, in 1855, the Royal Greenwich Observatory started transmitting time signals and in 1880, the Greenwich Mean Time (GMT) became the country’s official standard time.

Other countries created their own standard times and, in the late 1880s, the International Meridian Conference proposed a standardised 24-hour day, starting off at midnight GMT. Eventually the rest of the world began to use this system, shaping the time zones we know today.