Timed

Timed is an adjective describing something that is governed by time or measured with a timer, or something performed within a fixed duration. It derives from the verb time, indicating that an action or event is conducted under time constraints or at specified times. The sense can apply to both events and processes, and it is often used to contrast with untimed or open-ended activities.

Common uses include education, sport, technology, and everyday planning. Timed tests or exams have a set duration and are completed within that window. Timed events occur at scheduled times or within predetermined intervals, such as a timed race or a countdown in a game. In pharmaceuticals, timed or timed-release formulations describe products designed to release their active ingredient over a specified period. In computing, timed refers to operations controlled by a clock or timer, such as timed loops or timed events that trigger after a delay.

In computer science and systems engineering, timed automata are a formal modeling framework for real-time systems in which clocks constrain the timing of transitions and states. Timed constraints are central to real-time computing, embedded systems, and scheduling problems, where meeting deadlines and maintaining precise intervals are essential.

Etymologically, timed is the passive participle form of time, used as an adjective to indicate measurement or control by time. It appears across domains wherever duration, schedules, or countdowns matter.