See also:

• Reference: Time: Alternative Systems  (7)

Abbey Clock Clinic - Mark Headrick's Horology Page  www.abbeyclock.com Traditional horology website with information and mantainance tips. Technical descriptions and troubleshooting of escapements. Grandfather clocks, wall clocks, and watches.

Allan Variance -- Overview by David W. Allan  www.allanstime.com/AllanVariance Core algorithm of international time scale has multiple metrology applications, from atomic clock frequency characterization to definition of the meter. Equation, explanation and publications.

Antique Horology  www.antique-horology.org The Horological Foundation's directory of web sites for watches, clocks, instruments and barometers.

Clocks and Time  www.ubr.com/clocks Horological index for organizations, clock and watch museums, related software, mailing lists and links. Maintained by Gordon T. Uber.

Cumbria Clock Company  www.clockmaker.co.uk Company specialized in all aspects of work connected with church clocks, public clocks, and tower clocks which includes the full historical restoration of antique clock movements.

David Knight - Watchmaker from UK  www.davidknightwatchmaker.com Articles and pictures of the first two watches made by David Knight. Rich artistic pictures.

Daylight Saving Time  webexhibits.org/daylightsaving History of daylight saving time and how we use it to save energy.

Functionning of a Simple Mechanical Watch  collectorebooks.com/watch2/watch01.htm Explanation of the roles of components of a wristwatch.

The Horology Source  www.horologysource.com Gateway to all aspects of clocks, watches, timekeeping, and the science of horology.

Horology.com  www.horology.com Horology is the science of time, timekeeping and timekeepers. Organized collection of links to horological websites globally.

24 hour analog clocks  homepage.mac.com/pete.boardman/24hourclock The 24 hour analog clock and watch site. History, software, and the places to find clocks with 24 h dials.

How Stuff Works: Time  www.howstuffworks.com/time.htm Complete five-part explanation of time and how it is measured, including information about clocks, time zones, calendars, BC and AD.

How The Days of the Week Got Their Names  www.indepthinfo.com/weekdays/index.shtml A short history of the week and each day of the week.

Jens Olsen's Astronomical Clock  www.ateliera.dk/olsen.htm Description of the restoration of Jens Olsen's Astronomical Clock, a masterpiece in Copenhagen City Hall that consists of 15.448 individual parts.

Leap Year Calculation for Year 2000  h71000.www7.hp.com/openvms/products/year-2000/leap.html A response to a VMS problem report giving a detailed explanation of why 2000 is a leap year.

Louis Essen  www.btinternet.com/~time.lord Autobiography of the physicist who built the world's first operational atomic clock.

Ludwig Oechslin  www.ulysse-nardin.com/index2.jsp?ID_Page=10000L Curator at the Musée International d’Horlogerie (international watch museum) in La Chaux- de - Fonds, Switzerland. He has designed some of the most complex wristwatches in history.

Mark Frank's Home Page  www.my-time-machines.net Website showing the restoration of a French flat bed tower clock in great detail, step by step, as well as other information and links of tower clock sites.

National Association of Watch and Clock Collectors  www.nawcc.org Organization of watch and clock enthusiasts.

On Time  americanhistory.si.edu/ontime The Smithsonian Institute's exhibition on the changing ways we have measured, used, and thought about time over the past three hundred years.

"Orologio" at the St. Mark's Square Tower, Venice - Antica Orologeria Zamberlan  www.orologeria.com/english/tower/index.htm Website of Antica Orologeria Zamberlan, Italy. Includes technical and historical explanation of the restoration and controversy of the "Orologio" Tower at St. Mark's Square, Venice.

Pocket Horology  www.pockethorology.org National chapter of the NAWCC dedicated to collaborative research on the history and horology of pocket watches.

UNITAS Reference Site  www.unitas.netfirms.com UNITAS wristwatch and pocketwatch movements from 1898 to the present.