Although we’re all familiar with the concept of dividing geographical regions by time today, times zones are a relatively modern invention. Just like the more recent advent of the internet, time zones were created to simplify our lives — when the world began to run on a standardized time, it made global transactions and international travel less complicated. But as the saying goes, time is all relative, which is what makes time zones around the world so fascinating.
Greenwich Was the Logical Choice for the Prime Meridian
When it comes to time, the borough of Greenwich in London, England, is at the center of the world. That’s because Greenwich Mean Time (GMT) has historically been considered universal time — it’s even the time used by the international space station. In 1884, Greenwich was chosen as the center of world time for reasons of convenience. First, the U.S. had based its national time zones on a meridian that ran through Greenwich. Secondly, in the late nineteenth century much of the world’s commerce depended on maritime trading, and most sea charts also used the Greenwich meridian as the primary point of reference. As such, this particular meridian, which ran from the North Pole to the South Pole and crossed directly through Greenwich’s Royal Observatory, became the world’s Prime Meridian.
Set to 0 degrees longitude, the Prime Meridian is the line upon which GMT was established in order to set the standard for world time. In 1967, Coordinated Universal Time (UTC) was introduced as a GMT equivalent and an updated global time standard. At this point, GMT was technically reduced to just a time zone, although it’s still used as a common vernacular to tell the world’s time.
The International Date Line Makes Time Travel Real
In 1884, the International Meridian Conference was held in Washington D.C., with the goal of choosing a longitudinal equivalent to the equator and to standardize time throughout the world. At the conference, the Prime Meridian was established as a way to divide the Eastern and Western hemispheres just as the equator divides the Northern and Southern. At the same time, the 26 nations that attended the conference created another invisible line: the International Date Line (IDL). The IDL was created to demarcate the difference between one calendar day from the next. Set to a 180-degree longitude meridian, the IDL begins at both poles and then zig-zags around the globe, mostly through a remote section of open ocean.
Interestingly enough, since the IDL has no lawful status, countries are free to choose the dates they observe. Case in point: In 2011, Samoa decided to change its time zone by crossing the International Date Line and skipping an entire calendar day, thereby time-traveling into the future. The change was made in order to improve trade relations with Australia and New Zealand, two countries with whom Samoa conducts regular business.
Time Zones Were Invented for the Railroad
Before mechanical clocks were invented, people used sundials to tell the time. “Noon” was considered to be when the sun was at its highest point in the sky, due south. As a result, each town and city had its own version of time even after the introduction of mechanical timepieces. With the invention of the transcontinental railroad, however, the lack of standardized time became problematic. As people left one city and traveled by railroad across the country, watches had to be reset frequently to accommodate the different times at each station.
To solve this predicament, the U.S. borrowed the idea of time zones from Sir Sandford Fleming. A Canadian railroad engineer, Fleming had originally come up with the idea of dividing the world into 24 different longitudinally-based time zones, each with an hourly variation. The U.S. adopted this idea nationally, creating four different zones based on degrees of longitude. A year later, England, Scotland, and Wales followed suit, and eventually, the rest of the world did too.
One Size Doesn’t Fit All
When it comes to the geographical size of a country, the number of time zones is nothing but inconsistent. Some of the world’s largest nations have one time zone, while smaller nations have many. For example, even though the width of India is roughly the same distance between Utah and New York, the entire country has a unified time zone of GMT+5:30.
Originally, China had five geographical time zones — Zhongyuan, Longshu, Tibet, Kunlun, and Changbai — that were created in 1912. In 1949, however, the Communist party set all five of these time zones to Beijing’s GMT+8. As a result, some Chinese cities keep alternative workday schedules in order to stay aligned with Beijing. Conversely, France, a country with a more diminutive size geographically, has 12 time zones in total, thanks to its 11 overseas territories. And Märket, a tiny island in the Baltic Sea, has two different time zones, as it’s controlled on either side by Sweden and Finland.
Standard Time Isn’t Always On the Hour
Oddly enough, some countries don’t keep their time on the hour, instead choosing to use half or quarter hours to tell universal time. India, for example, is set to GMT+5:30, as is its neighboring country of Sri Lanka. Other countries that also are on the half-hour include Iran (GMT+3:30), Afghanistan (GMT+4:30), and Burma (GMT+6:30). Even more curious, Nepal is a country that runs on the quarter-hour, as its universal time is set to GMT+5:45.
If that’s not strange enough, Australia has five time zones, and only some of them are set to the half or quarter-hour on the clock. There’s no universal answer as to why the times are set this way; rather, it’s often a result of the politics of each nation. For example, India’s decision to set time on the half-hour was a compromise that accommodated New Delhi's location between two meridians. Setting the clock at the median hour was a concession that didn’t favor either longitude and presumably offset the fact that the large country runs on a single time zone.