Question

Why is standard time considered necessary?

Answer 1

The Earth has been divided into 24 time zones of one hour each. Each of these zones covers 15 degrees of longitude. As the local TIMe differs by 4 minutes at every longitude, it would create a lot of confusion regarding time for any country as a whole which may stretch across several longitudes. Therefore each country selects a central meridian and the local time of this meridian is the standard time of that country.