On Time - The Smithsonian Institute's exhibition on the changing ways people have measured, used, and thought about time over the past three hundred years. Antique Horology - The Horological Foundation's directory of web sites for watches, clocks, instruments and barometers. How The Days of the Week Got Their Names - A short history of the week and each day of the week. 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. 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. 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. 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. 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. Daylight Saving Time - History of daylight saving time and how we use it to save energy. Pocket Horology - National chapter of the NAWCC dedicated to collaborative research on the history and horology of pocket watches. David Knight - Watchmaker from UK - Articles and pictures of the first two watches made by David Knight. Rich artistic pictures. National Association of Watch and Clock Collectors - Organization of watch and clock enthusiasts. Horology - The Index - Horology is the science of time, timekeeping and timekeepers. Organized collection of links to horological websites globally. Leap Year Calculation for Year 2000 - A response to a VMS problem report giving a detailed explanation of why 2000 is a leap year. 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. Orologio: Restoration of St. Mark's Square Tower, Venice - Includes technical and historical explanation of the restoration and controversy of the tower. Richard White Clocks - Specialists in servicing, maintaining, restoring and repairing of tower, turret and church clocks. Provides details of their services, the automated mechanisms available, case studies and their news.