There are lots of time sites on the web. The World Clock is the most comprehensive, and includes sunrise and sunset times, international country and area codes, and latitudes and longitudes. If you'd like a cute clock interface for several major time zones, try International Time. For a nice, printable time-zone map to hang over your desk go to Time Zone Map or World Time Zone Map.
The Official U. S. Time is accurate to within a fraction of a second, and also shows the daylight/darkness map for the world.
