All they do is complicate things. In today's society where communication is easier across long distances, we should have a set Earth time. In each respective area, people will learn what time the sun rises and what time it sets. Communication and correlation over long distances would be simpler, and keeping track of world events would also be easier. Agree or no?
No. As for why they were created (in America at least. I dunno about other countries.) Originally time zones were a city by city basis. But when the railroads started getting built and manifest destiny and all that, there was confusion based on arrival and departure times and such. So, the government mandated time zones based on four different areas of the country; pacific, mountain, central, and eastern. There ya have it.