Other
Time and date.com: The World Clock Time Zones
This website has a variety of time resources. You can find a major city and its time. If you click on that city it will give you lots of information.
National Council of Teachers of Mathematics
Nctm: Figure This: What Time Is It In?
Can you figure this? If it is afternoon in San Francisco, California, what time is it in Cairo, Egypt? Explore positive and negative number values in this one page activity using time zones from different parts of the world.