A Walk Through Time
The Evolution of Time Measurement through the Ages

http://physics.nist.gov/GenInt/Time/

A web presentation from the NIST Physics Laboratory featuring:
*Ancient Calendars
*Early Clocks  
*A Revolution in Timekeeping  
*The "Atomic" Age  
*World Time Scales and Time Zones  
*NIST Time Services
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Calendars through the Ages

http://webexhibits.org/calendars/

From Webexhibits.org, explore the fascinating history of the human
endeavor to organize our lives in accordance with the sun and stars:
*Our Year
*A Variety of Calendars
*Our 7-Day Week
*Timeline of Interesting Calendar Facts