Figure 1. The official Time Zone chart from the Central Intelligence Agency, USA. You may need to refer to this while reading the text unless you are an excellent student of geography. Click to enlarge.
Time is Based on the Sun
Every day the sun travels from the eastern horizon to the western horizon*. At its zenith the sun crosses the North-South line. At this point, local noon time, the shadows are the shortest as the sun is more or less directly overhead, depending on your location on the planet and the time of year.
Figuring out the diameter of the Earth in ancient times
At certain well-placed water wells between the Tropic of Cancer and the Tropic of Capricorn, on certain days of the year, the bottom of the well is illuminated by a beam of light coming from the sun passing directly overhead precisely at noon. In other wells, elsewhere on the planet, on the same day at the same time, the beam of sunlight does not reach the bottom of the well, but comes in at another angle. That’s how certain ancient thinkers reasoned that the world was round since all the wells pointed directly down, toward the center of a globular Earth. With their data they were able to pretty closely figure out the Earth’s diameter through simple geometry.
An infinite number of noons every day
Now, if you think about it, a gradually moving sun produces an infinite number of local ‘noons’ every day around the world. Of course, until recently, that was never a problem. In the old days, no one was on a schedule and there were no good clocks around to put us on a schedule. So no one really cared what time it was. All we had to do was to get up with the sunrise and sleep after the sun had set.
Railroad train schedules
That all changed when the railroads came along. They had a schedule to keep to maximize their fares. They didn’t want any of their passengers to arrive late and miss the train. So the railroad tycoons came together and devised their own Time Zones: over 100 across the USA alone. Unfortunately, one hundred Time Zones were way too many. So in 1883 the USA was divided into four official Time Zones (see fig. 1). Suddenly everything became more manageable! Following that success, an international consensus for global Time Zones was introduced in 1884 and the results are also shown in figure 1 above.
Pocket Watches and Alarm Clocks
Keeping up with trains, meant people had to be on time. And businesses opened and closed at certain precise times. From then on everybody had to be to work on time, travelers had a train schedule to meet, and everyone had to buy their own clock or a personal pocket watch to keep pace with their busy scheduled world.
The ideal and the compromise
That previously mentioned international consensus divided the Earth into 24 longitudinal slices (from pole to pole), each 15 degrees in width, one for each hour of the day. Within each Time Zone all clocks were to be synchronized to the same hour, minute and second. Just outside of each zone – ideally – time would have been exactly one hour earlier or one hour later, depending on your directions of travel, west or east.
But that’s not how it happened to work out.
Setting the Prime Meridian
Due to English dominance at the time, and the fact that the antipodes were over the Pacific and Australia, that international consensus placed the Pime Merdian at Greenwich, England. So, when it is noon at Greenwich it is midnight and the start of a new day at the International Date Line on the opposite side of the Earth. All other Time Zones exist between these two and all other official Time Zones are referenced to these two imaginary lines running from pole to pole on opposites side of the Earth.
Every Time Zone has a distinct letter code. England is at Zulu time. Only Portugal, Iceland and Western Africa share Zulu time.
Atomic clocks on GPS satellites reference Zulu time (UTC) to computers and other devices worldwide. Masterclock products read these signals to synchronize electronic devices with GPS satellites and other linked devices around the world.
You might think that Spain would be on Zulu time since it is directly south of England. Not so. Nearly all of Europe is one hour later on Alpha time. So is a swath of mid-western Africa with country boundaries forming most of the eastern and western margins of the Time Zones.
Finland and the Baltics, the Ukraine and eastern Europe, much of the Middle East, and a swath of southern Africa are on Bravo time. Libya lies completely within Alpha time, but joins Egypt in Bravo time. Between Chad and the Sudan there is no Bravo time, so a trip from one to the other requires a two-hour resetting of your clock.
The Sudan is completely within Bravo time, but joins its eastern neighbors comprising the horn of Africa in Charlie time. In Europe only Belarus and a little land surrounding the Russian seaport of Kalinigrad are on Charlie time. Iraq, Saudi Arabia and the island of Madagascar round out this Time Zone memberhship.
The portion of Russia surrounding Moscow is on Delta time, despite the fact that most of this area is in Charlie time. Oman is the only other country on Delta time.
Kazakhstan and neighboring countries, including Pakistan, are on Echo time even though most of the area lies within Delta time. Iran splits the difference and sets its time a half-hour earlier than its neighbors. Afghanistan and India set their time a half-hour later.
Virtually none of the areas that use Foxtrot time are actually in Foxtrot time. These include the west-central areas of Russia. However, tiny Bangladesh and Nepal use and are completely within Foxtrot time. Burma is a half-hour later. Nepal, breaks all the ‘rules’ and is 15 minutes earlier than Foxtrot time.
Southeast Asia is on Golf Time. So is a Russian province west of Mongolia surrounding Novosibirsk, even though it is largely two Time Zones away in the Echo zone.
A strip of central Siberia (Russia) and all of Mongolia and China, the Philippines and western Australia are in Hotel time. China spans four time zones, but synchronizes the whole country under the one zone based on their more populated eastern seaboard.
The portion of Siberia (Russia) surround Irkutsk is on India time, even though that area is geographically two Time Zones away in Golf time. Korea and Japan are both on and within India time, sharing it with the western half of the island of New Guinea.
There is no Juliet Time.
The portion of Siberia (Russia) north of eastern China is on Kilo Time, even though it is largely over Hotel time, two Time Zones away. So is eastern Australia and New Guinea. Central Australia is a half-hour earlier.
A slim strip of Siberia (Russia) north of Valdivostok is on Lima Time, although geographically it is largely over India time. Here, if you fly south into Japan, it will be two hours earlier.
Mike and Yankee Time
With the International Date Line things get a little crazy. Eastern Siberia (Russia) and New Zealand are on Mike Time, along with a few south sea islands. For some reason the alphabetical pattern shifts here and goes to Yankee, which contains, as far as I can tell, no land areas. As we continue going East the Alpha order reverses (from Y to N) as you’ll see.
The International Date Line
Between Mike time and Yankee time is the International Date Line (IDL). When it is noon at Greenwich, England, it is midnight at the IDL and the beginning of a new day. One hour later only fifteen degrees of the Earth is in that new day. That’s why, whenever you cross the International Date Line going West, you enter that next day. And here is your only chance to go back in time, by one day, by flying east over the IDL. Only exactly at midnight at the IDL is the whole world experiencing the same day. Part of the IDL juts east over three Time Zones to encompass several Pacific island chains.
Just a few Pacific Islands are on X-ray time. It is largely oceanic and therefore less affected by poltical lines.
The westernmost Aleutians, Hawaii and the islands of French Polynesia are on Whiskey time. Hawaii does not follow Daylight Savings Time, so they are one hour earlier than the rest of Whiskey time in summer.
Virtually all of Alaska is on Victor time even though the bulk of Alaska is in the Whiskey and X-ray zones.
Uniform Time (Western Time Zone in the USA)
Western Canada and the West coast of the USA is in the Uniform Time Zone, along with the tiny Pitcairn Islands in the South Pacific.
Tango Time (Mountain Time Zone in the USA)
The Rocky Mountain States are in Tango time. Arizona is too, but does not observe Daylight Savings Time.
Sierra Time (Central Time Zone in the USA)
The central plains of Canada, the USA and most of Mexico and Central America are in Sierra Time.
Romeo Time (Eastern Time Zone in the USA)
Eastern North America and western South America are on Romeo time.
The tiny, easternmost provinces of Canada are on Quebec time. So is a swath of South America from western Brazil to Chile. Venezuela is a half hour earlier.
Much of Greenland, eastern Brazil and Argentina are on Papa time, even though Argentina straddles Romeo and Quebec time. Why the westernmost and easternmost tips of Greenland are not on Papa time is anyone’s guess. Almost no one lives there and most of those few don’t carry watches and there are no trains to catch! Tiny Greenland straddles five Time Zones, but that’s because the Time Zones converge near the poles. Newfoundland is a half-hour earlier.
Virtually no land areas are covered by Oscar time, although eastern Greenland occupies it.
Only a few Atlantic Islands, including the Azores, are on November time.
But Wait, There’s More!
As you can see, politics, as much as the postion of the sun, plays a part in determining the boundaries of Time Zones and the local time. Only across vast stretches of open ocean are the Time Zone lines more or less straight from pole to pole, as they should be.
Where All the ‘Rules’ Go Out the Window
Everyone knows, if you walk around the North or South Pole, you can cross all 24 times zones in less than a minute, because all the Time Zones converge at those points.* A little further south, across northern Siberia, there is another two-hour jump between Time Zones. As in the Sahara (see Bravo time, above), with so few people and such a harsh environment, nobody is complaining.
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Time is important. That’s why we’re in this business.
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*At the poles, of course, things are different. The sun simply goes around the horizon, never rising more than 23 degrees (the tilt of the Earth). For half the year the sun remains below the horizon casting a perpetual twilight glow during the spring and fall and creating days without sunshine for the winter or summer months, depending on the pole you happen to be on.