Qlock

Keep track of the time around the worldQlock helps you see the time in as many different cities as you can fit on the screen. There are five different sizes of clock and each one can have an alarm. They also diplay the hours different from the local time. You can colour code the clocks and they snap onto each other so it is easy to arrange them onscreen.

If a particular city in not included in the list of 500 available, you can add you own and include details of daylight saving changes that apply to it.

Qlock is also completely free so there is no reason not to give it a try.