Based on the information obtained from a coordinate map, we can use the Prime Meridian, or Greenwich Meridian, to divide the Earth into 24 sections known as time zones. Time zones are imaginary lines that divide the Earth to establish time divisions and are a useful tool for organizing time around the globe.
In this article we are going to tell you how time zones work and how important it is.
What are time zones
Since our planet is constantly rotating on its axis, the time is not the same in different parts of the world. While it is daytime in Spain, it is still dawn in the Americas. Therefore, if we want to establish a time zone for everyone, we must take these differences into account. This is why time zones exist.
Time zones are created by dividing our planet into 24 sections using the prime meridian as a reference. Meridian lines can be found on a coordinate map . This becomes a useful resource for organizing time. Each time zone measures 15 degrees. This means that to divide the 360 ​​degrees of the Earth, 24 sections must be created. Each section indicates the number of hours it takes the Earth to rotate on its axis. This is how we measure the time it takes for a day to complete one rotation.
The 15 degrees measured by each time zone in what is divided on the planet, corresponds to one hour. Therefore, among the 24 sections in which the land is divided correspond to 24 hours a day.
How they are calculated
To establish a consistent time across the globe, time zones must be calculated correctly. Time zones are governed by a time standard known as UTC (Coordinated Universal Time). These universal time coordinates are derived from International Atomic Time. This time is a scientific standard that measures the passage of time on atomic clocks at various points around the world. Currently, it is the most accurate model for calculating time.
Time zones around the world are calculated using the Prime Meridian in London as a reference point. East of this meridian, one hour is added for each time zone. Conversely, west of the meridian, one hour is subtracted. The reason for adding or subtracting hours depends on the Earth's rotation. The planet rotates from west to east. Therefore, the time zone calculations for zones moving in this direction are called positive deviation, while those calculated in the opposite direction, that is, westward, are called negative deviation.
Examples of time zones
Let's show some examples of time zones to make it easier to understand. You can quickly calculate the time in a specific region or city by knowing its time zone. You need to remember whether this zone is negative to subtract hours or positive to add hours. Here are some examples:
Some of the cities that lie on the Prime Meridian have time zones UTC ± 00:00 and include, for example, Mali, Ivory Coast, Greenland, Mauritania, Gambia, and Portugal , among others. You can find more information about the impact of the Prime Meridian on world geography in this article, which helps to understand its significance.
Some cities whose time zone is UTC -05:00 (five hours behind) are Mexico, Colombia, Canada, Peru, and some regions of Brazil. In this case, we see that the time zone is negative, meaning that five hours must be subtracted from the time indicated by the prime meridian. If it's 10 p.m. in the cities located on the prime meridian, it's 5 p.m. in all regions with this time zone.
Let's look at more extreme examples, such as UTC -12:00 (twelve hours less): here we find Baker Island and Holand Island. Here we can see that if it's 7 p.m. on the zero meridian, it's 7 a.m. on these islands.
Now we move to the other side where we need to add hours. With a time zone of UTC +06:00 (six hours ahead), we find Bangladesh, Russia, and Bhutan, among others. Here we can see that if it is 9:00 AM on the meridian, it will be 3:00 PM in these countries.
What are they for
Many people wonder what time zones are for. The main purpose is to allow people to tell time around the world. Time zones are based on different meridians, as determined by the authorities of each country or region. Each type of time zone has certain consequences for daily life in each country.
With the creation of the time zone system, we have a 24-hour measurement of time based on the prime meridian. This makes calculating the time in any location much easier and more practical. The initiative to create a global time system governed by time zones and based on the prime meridian came from the Scottish-Canadian engineer Sandford Fleming . This method of measuring time worldwide emerged at the end of the 19th century.
Since these time changes occur depending on the area of ​​the world we are in, there is a phenomenon known as jet lag. It involves the inability to adapt to different time zones and the impact on the circadian rhythms of people who travel frequently. For example, for flight attendants and pilots, jet lag often significantly affects their daily lives. This is because, when they arrive in a country far from their home country, the time zone is not the same, nor are the activities they perform there.
I hope that with this information you can learn more about the different time zones.