Question

Why is it necessary for some countries to have morethan one time zone?

Answer 1

The countries tend to be very large in terms of geography and covers huge landmasses.

For example

RUSSIA

It has 11 time zones

Some countries overcome this problem by taking out the mean of the time zone.

For example

INDIA

It has difference of two hours from Gujarat to Arunachal Pradesh but the whole time followed in the country is the mean of both the time zones i.e. 5 30 (standard time merdedian)

Answer 2

This is because the earth is a geoid and spins ( is not fixed ) the sun is stationary and if all the countries had one time zone, earth should spin at a velocity of infinite km/hr which is not possible.

I hope u understood