United By Sun, Divided By Time

We all know that a day is 24 hours long, with the duration of day and night varying throughout the year. If you think keeping track of time is hard as it is, wait until you hear about the time zones used to keep track of different times across various regions of the world.

Prepare to let your mind be blown, and your jaw dropped in wonder. Let us travel through the time zones of this beautiful planet that we call home.

What Are Time Zones?

A time zone can be defined as a geographical area that observes a uniform standard time for legal, commercial and social purposes.

As the Earth completes one rotation in 24 hours, it rotates 360 degrees every day and 15 degrees every hour. Though it would make sense to divide the Earth into 24 time zones based on the longitudes,  boundaries between countries and their subdivisions are used to define time zones. It makes complete sense for areas in frequent communication to keep the same time.

The Need For Time Zones

If you were to go in space and point a flashlight towards the Earth, only a specific part of the Earth would receive light, whereas the remaining part would be in complete darkness.

Similarly, when the sun shines on a particular region of the Earth, it experiences sunrise, marking the beginning of morning for that region. Owing to Earth’s rotation as a location on Earth rotates into the sunlight, it experiences sunrise. When the location rotates out of sunlight, it experiences a sunset.

Imagine the whole of Earth had a single standard time zone. It would be the middle of the day at noon in some places, while some other places would experience morning, evening or even night. That doesn’t sound right.

Since different regions of the Earth enter and exit daylight at different times, we require different time zones.

The History And Origin Of Time Zones

Geographically people have always lived in different time zones. But it was much more complex since every town had its own official clock that was set to 12 o’clock when the sun was highest in the sky each day. Then clocks all over the town were adjusted every single day to show the same time at noon.

As advanced means of transport brought the world closer, keeping accurate time became more complicated. When people started to travel across the width and breadth of North America via trains, keeping track of the multiple local time zones became a challenge. At one point in time, every train station in the United States alone was forced to keep track of 75 time zones across the country.

To further simplify the process of timekeeping for every zone, a group of scientists in the 1800s came up with the concept of the Standard Time System. To formulate the time zone map, they studied the Earth’s movements and geography.

If you look closely at a Globe and the markings of latitude and longitude on it, you will find that the distance between two longitudes is the largest at the equator, and it gradually shrinks to zero at the poles due to the curvature of the Earth. The equator is about 24,902 miles long; this makes the distance between two longitudes at the equator to be around 1,038 miles.

For the sake of having a definite reference point, the imaginary longitudinal lines begin at Greenwich, a suburb of London. The longitude passing through Greenwich is thus called the Prime Meridian.

The time at Greenwich is referred to as the Greenwich Mean Time (GMT). When you move by 15 degrees to the west of Greenwich, every 15-degree section or time zone is one hour earlier than GMT, while each time zone to the east of Greenwich is an hour later.

Having different time zones ensures that no matter where you live on the planet, your noon shall be the middle of the day with the sun at the highest point in the sky, while midnight is precisely the middle of the night.

Why Is The Number Of Time Zones A Lot Higher Than 24?

Having 24 time zones divided equally by the imaginary longitudinal lines makes perfect sense since it simplifies timekeeping and maintains uniformity of time zones all over the Earth.

Then why do countries prefer to have their own time zones?

While the longitudes make for perfect division, more often than not, one time zone occupies regions of more than just one country. Since countries function as individual units in business, policies, and rail timings, countries with a sizeable longitudinal expanse divide their countries into multiple time zones to ease timekeeping.

Bizarre Time Zone Facts

Large countries such as the U.S.A, Canada, and Russia have multiple time zones to ensure that the region’s local time isn’t too far off from the solar time. France has 12 time zones, with only one time zone on the mainland. Whereas France owes its 11 other time zones to its island occupancies. You will be astonished to read about the different pacific timezone phenomenon of the U.S.A.

Despite having 11 standard time zones, Russia uses only nine for business and political purposes.

Apparently, to unite with the rest of the country and streamline business relations with Moscow, Putin swiftly abolished the time zones overnight; subsequently, the Udmurt Republic and Samara Oblast switched from GMT +03:00 to GMT + 04:00, catching up with Moscow. Meanwhile, Kamchatka and Chukotka joined the time zone of Magadan Oblast, bringing themselves to GMT +11:00, eight hours ahead of the capital.

Despite stretching across three standard time zones, China adheres to only one single time zone. Due to this anomaly, the solar time doesn’t correspond to the local time. In Beijing, the solar noon occurs not at noon but at 2:56 pm.

Furthermore, various regions of the world follow the Daylight Savings Time (DST) to adhere to the sun’s cycle by setting their clocks forward by an hour in spring and backward by an hour in fall.

If you’d like to explore the concept of time zones even further, make sure to read about the International Date Line (IDL) and the three additional time zones it creates.