How many time zones are there around the world?

There are 39 separate time zones. You can find specific details about them in Wikipedia's files at http://en.wikipedia.org/wiki/Time_zones

Yes, as a matter of fact the Earth's surface is divided into 24 standard time zones´┐Żone for each hour in the day. Each zone is roughly 15 degrees of longitude wide (longitude is a measure of how far east or west a given place is on the globe; each degree of longitude is spaced 69 miles [111 kilometers] apart at the equator and narrows as it reaches the poles). The boundaries of some time zones follow national borders and thus are irregular in shape. The time within each zone is constant; each time you enter a new zone the time changes by one hour.