Jabarkan and Immanuel Kant, dari Waktu dalam bahasa sunda

holds that time is neither an event nor a thing, and thus is not itself méasurable nor can it be traveled.

Temporal méasurement has occupied scientists and technologists, and was a prime motivation in navigation and astronomy.

Periodic events and periodic motion have long served as standards for units of time. Examples include the apparent motion of the sun across the sky, the phases of the moon, the swing of a pendulum, and the béat of a héart. Currently, the international unit of time, the second, is defined in terms of radiation emitted by caesium atoms (see below).

Time is also of significant social importance, having economic value ("time is money") as well as personal value, due to an awareness of the limited time in éach day and in human lifespans.