Watch Glossary

Alarm

The watch/clock alerts you with an audible or inaudible (such as a vibration) alarm at a pre-set time(s). Not to be confused with the repeater function found in some fine watches.

Amplitude

The degree of swing in a balance-wheel or pendulum.

Analog - Digital Display

A watch that shows the time by means of hour and minute hands (analog display) as well as by numbers (a digital display).

Analog

A watch that shows the time using hour and minute hands.

Annual calendar

A watch showing the day, date (in an aperture, or opening in the dial) month and 24 hours, adjusting automatically for short and long months. Such a calendar needs setting only once a year - from the end of February to the 1st of March.

Aperture

A window in the dial revealing an indication on a disc beneath the dial, such as a date, month, moon, etc.

Arbor

The shaft of a wheel or of a key-winding system.

Astronomical

Indicates a watch with any indication of time depending on the sun, moon or stars, such as: equation of time, sun hand, zodiacs, time of sunrise and sunset, moon-phase, sidereal time, and star disc.

Atomic second

The world's absolute time unit that defines the second as more than 9 billion periods. One watch that takes advantage of that is the BeepwearPro, produced by a joint venture between Timex and Motorola, resulting in a timepiece which bases it’s time display on a radio signal (found within the continental United States) in turn based on an atomic clock output.

Automatic Winding: (also referred to as just “automatic”)

A watch with a mechanical movement (as opposed to a quartz or electrical movement) with the addition of the watch’s reserve power being maintained by the motion of the wearer's arm rather than through a daily winding process. A rotor (also referred to as “pendulum”) that turns in response to motion winds the watch's mainspring. If an automatic watch is not worn for a day or two, it is normal to wind down and will need to be hand wound to restart.