"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.
24 hour analog clocks: The 24 hour analog clock and watch site. History, software, and the places to find clocks with 24 h dials.
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.
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.
Antique Horology: The Horological Foundation's directory of web sites for watches, clocks, instruments and barometers.
Clocks and Time: Horological index for organizations, clock and watch museums, related software, mailing lists and links. Maintained by Gordon T. Uber.
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.
David Knight - Watchmaker from UK: Articles and pictures of the first two watches made by David Knight. Rich artistic pictures.
Daylight Saving Time: History of daylight saving time and how we use it to save energy.
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.
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.
Horology.com: Horology is the science of time, timekeeping and timekeepers. Organized collection of links to horological websites globally.
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.
How The Days of the Week Got Their Names: A short history of the week and each day of the week.
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.
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.
Leap Year Calculation for Year 2000: A response to a VMS problem report giving a detailed explanation of why 2000 is a leap year.
Lincolnshire Branch of the British Horological Institute: News, events, activities and general information maintained by BHI members.
Louis Essen: Autobiography of the physicist who built the world's first operational atomic clock.
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.
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.
Pocket Horology: National chapter of the NAWCC dedicated to collaborative research on the history and horology of pocket watches.
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.
R.A. Braithwaite: Educational site Elliott clocks, how they are built and how to look after them.
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.
UNITAS Reference Site: UNITAS wristwatch and pocketwatch movements from 1898 to the present.