The first clock displays the time based on your location when you set up iPhone. Add other clocks to show the time in other major cities and time zones.

The World Clock screen, with the Edit button in the upper-left corner and the Add clock button in the upper-right corner. Five horizontal bands display the time in five different cities around the world. Along the bottom, from left to right, are the World Clock, Alarm, Stopwatch, and Timer tabs.