why do we have time zones around the world


spins on an called its. Every 24 hours, the Earth makes a complete
Б or one full Б on its. We call each full a. Imagine shining a flashlight at a. Only part of the would receive light, while the opposite side of the would be dark. As rotates, different parts of Earth receive sunlight or darkness, giving us and night. As your on Earth rotates into sunlight, you see the. When your rotates out of sunlight, you see the Sun set. If we had one single time for Earth, noon would be the middle of the in some places, but it would be, and the middle of the night in others. Since different parts of Earth enter and exit daylight at different times, we need different time zones. In the late 1800s, a group of scientists figured out a way to divide the world into different time zones. In order to build the time, they studied Earth\’s movements. As Earth rotates on its, it moves about 15 degrees every 60 minutes. After 24 hours, it has completed a full circle of 360 degrees. The scientists used this information to divide the planet into 24 sections or time zones.


Each time is 15 degrees of wide. Distance between the zones is greatest at the and shrinks to zero at the poles, due to the of Earth. Since the is approximately 24,902 miles long, the distance between time zones at the is approximately 1,038 miles. The dividing lines begin at Greenwich, a suburb of London. The primary dividing line of is called the. is the angular distance between a point on any meridian and the at Greenwich. The time at Greenwich is called (GMT). As you move west from Greenwich, every 15- section or time is an hour earlier than GMT, while each time to the east is an hour later. Having different time zones means that no matter where you live on the planet, your noon is the middle of the when the sun is highest, while midnight is the middle of the night. Let\’s take a closer look at how this works. Let\’s say you live in Charlotte, North Carolina, and you have a cousin who lives in Madrid, Spain. Charlotte is five time zones to the west of Greenwich, which is written as GMT -5.

Madrid is 1 section east of Greenwich (GMT +1). This means Charlotte and Madrid are six time zones apart. When your cousin is eating lunch at noon Madrid time, you are probably just getting out of bed to get ready for school. This is because at 12:00 p. m. in Madrid, it\’s only 6:00 a. m. in Charlotte. On the other hand, if you wanted to chat with your cousin online after dinner at 6:00 p. m. , it would already be midnight in Madrid! Increasing globalisation in the Victorian era meant a need to standardise time zones, as businesses began to operate across wider areas and world travel became easier with the advent of the railway. The in 1884, attended by representatives from various countries, led to the creation of the 24 time zones we use today. The zones are based on 24 longitudinal meridian lines that run from the north to south poles. The prime meridian, determined by the 1884 conference, runs through Greenwich, in the UK, giving us.

Other time zones are counted to the east and west of this line, either plus or minus hours from GMT. Each country sets its own time zone within this framework, so some zones extend beyond the meridian for convenience, while others, like India, take on half hours. even extended its time zone 600 miles east in 1995, to include Caroline Island in the same zone (and, as it straddled the opposite the GMT meridian, the same date) as the country\’s other islands. The development of the world wide web in the 1990s led to calls for a standardised internet time, as people in cyberspace were no longer bound by geography. Swatch even invented a concept called that split each day into 1,000 beats on a decimal system, eradicating time zones entirely. For those of you who don\’t operate on Internet Time, this spreadsheet shows the time zone in 195 countries, extracted from our series. в в Can you do something with this data? Flickr Please post your visualisations and mash-ups on our or mail us at в в в

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