Geospatial Resources: Google Earth Time Zones Clock
Here is a neat little Google Earth Time Zones file that has often been helpful on many of my field trips when trying to remember where time zones start and stop. Just open the file in Google Earth, then point and click your location to get info on that time zone.
The file overlays a custom polygon time zone map, then allows the user to click anywhere in the world to produce a pop up bubble
containing a running clock with the time zone (GMT) and the current time for that area, although does not seem to make the daylight savings adjustment.