Originally, a timepiece was a highly accurate watchmaking instrument designed to measure and conserve time. Among other things, it served as a reference, giving the exact time around the world.
Timepieces were instruments such as marine chronometers, or much later, quartz clocks or stronomical clocks.
Nowadays, the term retains this meaning, but has broadened, taking on the more general meaning of a watch as well. From many watch enthusiasts use the term «timepiece»; to refer to a watch of very high quality.
In any timepiece, the passage of time is an obsession, so TACS has devised several ways of represent, see and measure the time passing.