A question about time zones?

Question

So i was thinking about time zones, since most countries ( i think so?) have one time across the whole area of the country, So lets imagine a scenario, Person A is on the border of 2 countries called A and B and Person B is on the side of the country B(A Being on the side of country A), The time in A's Watch is 11:00 but the time in B's Watch is 11:30 so even though they are a few meters apart, they still have different times,since time zones were invented because sometimes some parts of the earth had light( DAY!), and some did not(Night!), so everybody had different times corresponding to their phase of the day like 12:00 is Noon, so is not this system wrong?( Again i have to say that i can be totally wrong)

Answer 1

Well, a few approximations here.

Lots of countries have more than one time zone (US, Russia, obviously. But even mine, France. And not only because of our oversea territories. Ouessant, which is 15 miles from continental France, has its own time zone. I guess there are some strange "exception" like that everywhere. I know there are some in US. Where some small cities have their own timezone, surrounded by another timezone)

Another approximation, is that timezone are (except for one exception, I don't recall where) separated by a integer number of hours. So time in A's watch is 11:00 and in B's watch 12:00, not 11:30

But it doesn't matter.







So, apart from those approximation, sure, you're right: if what we want, over any other consideration, were anyone to live with a time that perfectly match the "phase of the day" (for example to have a watch display 12:00 when the Sun is at its highest point), then, there would never be any of the discontinuity you describe (2 people living a few meters for each other, and having different time)



But that would not give an extraordinary advantage. I mean, do you have the feeling to be so accurately related to the Sun? If that were the case, nobody would need a watch, anyway.

So, the point is it doesn't change a lot to live 1 hour before or after.



And that would be painful. That would meen that there is an infinity of timezone!

Each time you walk 1 step toward the west, you have to change the time of you watch (0.003 seconds less).

Each time you drive a dozen of mile, you have to change the time of your watch (1 minute, more or less, depends on the direction you drive and your latitude)



Nobody (except the people who live on the very same meridian as you are) will have the same time as you.

Impossible to look at a TV program without doing very precise calculation. The delay between the indicated hour and the real hour would be different for any person)



So, the compromise is to create timezone that are large enough, to have the comfort to have the same time in a large zone (as long as you stay in the zone, you don't change time. If your TV emetter is in the same timezone as you are, no computation to do).

And small enough, so that the difference between the official time in the time zone, and the "real" time (phase of the day) is not disturbing.



Timezone of 1 hour (that is approx 1000 miles, at the equator) are a good compromise. 1000 miles is large enough so that most of the countries, as you said, can fit entirely in it. So no time change in the whole country.

(And if the country is bigger, it still have the option to have a difference greater that 1 hour between the "sun time" and the official time. Even 2 hours is still not very disturbing. Even China have a single timezone !)

And is small enough to be not disturbing (if your watch display 11:30 or 12:30 when the sun is at its highest point, you wont even notice. It is not like we were asking you to have your midday lunch at 17:00)



Plus, timezone of 1hour, exactly, makes it easier to compute differences when you have to switch from one timezone to another (when you travel, when you chat with your neighbor the other side of the border, when you watch a TV from a station located at another timezone, etc).

Answer 2

Your totally wrong. There are 24 main time zones around the World. The United States has four times zones just in the 48 States and if you count Hawaii and Alaska there are more.

Small Countries like England lie in only one Time Zone.

Times zones are Based on Longitude. Each time zone is 15 Degrees of Longitude Wide.

You are correct about two people being on the Border of Two Time Zones. Take Yuma Arizona and Winterhaven Calif. Right next to each other, separated by the Colorado River which is also the Border between two times zones.

You can stand on one side of the Bridge and I could be on the other side and there is a ONE hour difference between us.

Answer 3

Yes that is correct though usually the time zones are an hour different not a half hour. People who live near the lines get used to dealing with switching back and forth.And why some parts of the USA have odd configurations of the time zone change lines.

Answer 4

time zones were invented to "stabilize" the times in certain regions SO THAT THE LOCAL TRAINS ALL KEPT THE SAME TIME.



Before the trains started running, NOON was determined by when the sun was directly overhead. When it was "noon" at your location, just a few miles east of you it was 12:30 PM, and a few miles west of you it was 11:30 AM. Therefore, if you said "The train arrives at 12 Noon", people would aks, "Do you mean HERE, or in Eastville, or in Westville?"



Time Zones were invented to stabilize the times in nearby cities. AFTER the times zones took effect, when it was noon HERE, it was ALSO nnon in both Eastville AND Westville.



The United States decided to follow this standard, Europe, with no European Union at that time, let each country decide what time it decided to take, and generally each country was in one time zone. Countries in Russia and chine simple decide to take the same approach, regardless of their physical size.



Wikipedia has an excellent article on Time Zones