Horology

Horology ("the study of time", related to Latin "horologium" from Greek , "instrument for telling the hour", from "hṓra" "hour; time" and -o- interfix and suffix "-logy") is the study of the measurement of time. Clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. In current usage, horology refers mainly to the study of mechanical time-keeping devices, while chronometry more broadly includes electronic devices that have largely supplanted mechanical clocks for the best accuracy and precision in time-keeping.
People interested in horology are called "horologists". That term is used both by people who deal professionally with timekeeping apparatus (watchmakers, clockmakers), as well as aficionados and scholars of horology. Horology and horologists have numerous organizations, both professional associations and more scholarly societies. The largest horological membership organisation globally is the NAWCC, the National Association of Watch and Clock Collectors, which is USA based, but also has local chapters elsewhere.
Museums and libraries.
There are many horology museums and several specialized libraries devoted to the subject. One example is the Royal Greenwich Observatory, which is also the source of the Prime Meridian (longitude 0° 0' 0"), and the home of the first marine timekeepers accurate enough to determine longitude (made by John Harrison). Other horological museums in the London area include the Clockmakers' Museum, which re-opened at the Science Museum in October 2015, the horological collections at the British Museum, the Science Museum (London), and the Wallace Collection.
In Upton, UK, at the headquarters of the British Horological Institute, there is the Museum of Timekeeping.
One of the more comprehensive museums dedicated to horology is the Musée international d'horlogerie in La Chaux-de-Fonds (Switzerland). The Musée d'Horlogerie du Locle is smaller but located nearby. One of the better horological museums in Germany is the Deutsches Uhrenmuseum in Furtwangen im Schwarzwald, in the Black Forest. The two leading specialised horological museums in North America are the National Watch and Clock Museum in Columbia, Pennsylvania and the American Clock and Watch Museum in Bristol, Connecticut.
The eastern French city of Besançon has the Musée du Temps (Museum of Time) in the historic Palais Grenvelle.
An example of a museum devoted to one particular type of clock is the Cuckooland Museum in the UK, which hosts the world's largest collection of antique cuckoo clocks.
One of the most comprehensive horological libraries open to the public is the National Watch and Clock Library in Columbia, Pennsylvania. Other good horological libraries providing public access are at the Musée international d'horlogerie in Switzerland, at the Deutsches Uhrenmuseum in Germany, and at the Guildhall Library in London.
Another museum dedicated to clocks is the Willard House and Clock Museum in Grafton, Massachusetts.
In Serpa and Évora, in Portugal, you can visit Museu do Relógio
Organizations.
Notable scholarly horological organizations include: