Question

why do some countries have more than one timezone

Answer 1

Due to a relatively larger latitudianal extent.

Eg us Russia

Answer 2

Here is answer ......


Time zones are based on the fact that it takes one hour for the earth to rotate 15 degrees on its axis. This means that if the sun is at its zenith at some location (local noon—when it is at highest part of its arc across the sky) it is an hour later 15 degrees of longitude east of that point and an hour earlier 15 degrees of longitude west of that point.

That means that large countries that span more than 30 degrees of longitude usually have different time zones. Although there are a couple of countries that ignore this and have only one time zone for political reasons.

Prior to the adoption of timezones in the 19th century EVERY town had a different time basis set by measuring the local noon . There is/was nothing wrong with that because there was no practical reason for different towns to have a common time basis. People and information could only travel as fast as a horse could run or carrier pigeon fly. Astromers, navigators and surveyors cared because they calculated longitude based on time.

Then along comes the telegraph and the railway.

The telegraph allowed messages to move pretty close to instantly from points with different local noons. This was confusing.

The railways used telegraphy to dispatch trains on the same track. You can image the problem two trains are on the same track using clocks based on towns with different noons! Crash!

This led to the adoption of ‘Railroad time’ where each railroad had it’s own master time (usually that of it’s headquarters). This solved the dispatch times within a railroad, but meant that train stations had to have separate clocks for each railroad served by the station.

By the mid 19th century time zones were being created politically to resolve this problem.


Hope this will help you....