| A Walk Through Time|
The National Institute of Standards and Technology presents the history of time and time keeping from ancient calendars and early clocks to modern time services.
| Official U.S. Time|
A public service provided under the cooperation of the National Institute of Standards and Technology (NIST), and the U. S. Naval Observatory (USNO); reading from these agencies contribute to world time, Coordinated Universal Time (UTC).
| The World Clock|
Provides a table of times in various cities around the world; sort by country or time zone, shows current or fixed past, present or future time.