A Walk through Time
History of timekeeping from ancient to modern times.
(at NIST)
Calendars through the Ages
Systems of counting the days, months, and years.
(at webexhibits.org)
Daylight Saving Time
When and why do we change our clocks?
(at webexhibits.org)
ClockWorks
Illustrated mechanisms of many historical clocks.
(at Britannica)
It's About Time
Advances in timekeeping accuracy and atomic clocks.
(at University of Wisconsin)
The Quartz Watch
What's inside your wristwatch? See stories and timeline.
(at Smithsonian)
Disclaimer Note: Linking to these sites does not imply recommendation or
endorsement of the information or commercial products by NIST or USNO.