Question: In other countries, why is there a different time of day and not the same in ever place?

Amy Birch answered on 11 Jun 2012:

Hi genta08, thanks for re-sending this question. Sorry it’s a bit later in the day, I had experiments to do (and the football to watch…)
This to do with the fact that the earth is always rotating around the sun, and so when it is the day time in one place it is nighttime in another place. People have always used the sun to judge the time of day, and so time was always set locally.
Because the earth is a curved and not flat, there are differences in when the sun is in the middle of the sky (midday) even over quite short distances (for example between London & Edinburgh there is 12 minutes difference) so to make things easier for people (otherwise we’d have to change our watches all the time!), uniform time zones were created so that everyone could know what time it was all over the world. This means that it is not exactly the same as local, solar time (which is going by the sun) but it makes travelling and doing business in different countries a lot easier to do.
Hope this answers your question! 🙂