Do you know someone who loves geography, maps, and unusual time zone trivia? If so, she will enjoy the following challenge. The exercise also introduces children (grades 4-6) to time zones, the World Clock, the International Dateline, the Prime Meridian, daylight saving time, and much more. There are many internet resources (or apps) for instruction including, World Time Zone, World Atlas, and Timeanddate.com. Timeanddate.com also helps answer the question: Why do we have all these time zones?