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

Horology - A Great Hobby  
   A very basic introduction to how electric clocks work, with animated pictures. Also a collection of cheap electric clocks with pictures and descriptions.
   http://home.clara.net/steve.thackery/clocks/horindex.htm

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

Leap Year Frequently Argued Questions  
   A humorous approach towards explaining the nature of leap years, in particular why 2000 is a leap year.
   http://world.std.com/%7Edpbsmith/leapyearfaq.txt

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

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

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

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

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

Online Clock Building  
   Watch a master clockmaker building a clock movement from scratch. Hundreds of photos and drawings, plus a complete description of the process and CAD plans.
   http://www.onlineclockbuilding.com

Towerclocks.org - Towerclocks in the World  
   Descriptions, photos and history of tower clocks in the world (English, Español, Português).
   http://www.towerclocks.org

Cumbria Clock Company  
   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.
   http://www.clockmaker.co.uk

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

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

Mark Frank's Home Page  
   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.
   http://www.my-time-machines.net

The History of Clocks and Watches  
   Learn about the history of clocks and watches, and discover the evolution of timekeeping devices from the first primitive sundials to the ultramodern atomic clocks. Includes a timeline.
   http://home.rochester.rr.com/kjmpage/clockshistory.html

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

David Knight - Watchmaker from UK  
   Articles and pictures of the first two watches made by David Knight. Rich artistic pictures.
   http://www.midknight.fsnet.co.uk/david.html

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

Hampton Court Clock  
   The story of the famous Astronomical clock at Hampton Court Palace. By the author of the original official guide books with the extra omitted information.
   http://pages.zoom.co.uk/cosmicelk/hamptoncourtclock.htm

Lincolnshire Branch of the British Horological Institute  
   News, events, activities and general information maintained by BHI members.
   http://homepage.ntlworld.com/heather.hobden1/lincsbhi.htm

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

R.A. Braithwaite  
   Educational site Elliott clocks, how they are built and how to look after them.
   http://www.braithwaitesjewellers.co.uk

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

Clock a History  
   A brief history of time keeping. How mankind has used the sun, water, candles, sand, pendulums, springs, electronics, tuning forks, and quartz crystals, to tell time.
   http://www.ernie.cummings.net/clock.htm

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

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

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

Pulsynetic Electric Clocks  
   Description, pictures and diagrams of many of the horological products made before 1945 By Gent's of Leicester GB, including a rare Observatory controlled transmitter.
   http://mysite.wanadoo-members.co.uk/Pulsynetic

Layman's Guide to the Gent's Electric Turret Clock  
   A Layman's Guide to the working and restoration of a Gent's Pulsynetic Waiting Train Electric Pendulum Turret Clock.
   http://mysite.wanadoo-members.co.uk/waitingtrain/index.jhtml