At a suitable time. / In time; before an appointed time; with time to spare.

Money is wasted (in lost wages, missed opportunities, etc.) when a person's time is not used productively; time is valuable and should not be wasted.

The time when an airplane, etc, is scheduled to depart.

Time, as measured by an atomic clock.

(informal) Any amount of free time to sleep or rest.

The interval between the reception of a stimulus and the initiation of a response

To occupy oneself for a period of time.

(originally aviation) Coordinated Universal Time.

plural of time scale

(historical) The limit on the amount of airplay of recorded music in any given 24-hour period.