Here are some exhibits related to Time and Frequency...
A Walk Through Time
An illustrated history of timekeeping from ancient to modern methods.
Calendars Through the Ages
A short overview of our current calendar, as well as other ethnic and historical calendars. (At webexhibits.org)
The Quartz Watch
Discover the fascinating stories behind the invention of the quartz watch. (At the Smithsonian Lemelson Center)
Daylight Saving Time: Saving Time, Saving Energy
Daylight saving time, its history and why we use it. (At webexhibits.org)