Just before it is too late; in the nick of time; last-minute.

The hour after midnight, when witches and other supernatural beings were thought to be active, and to which bad luck was ascribed.

(time) fifteen minutes.

A time of day, usually in the afternoon or early evening, when a bar or pub offers its drinks at a discounted price.

(figuratively) The hour at which any major event planned for the future is set to begin, as used in United States military.

(idiomatic) The times of the day when traffic jams are commonplace, due mainly to people commuting to or from work.

The hand of a clock or watch face that revolves twice each day and indicates the hours.

(units of measure) A unit of time reckoned as ¹⁄₁₂ of a day's daylight or nighttime, varying according to season, latitude, and local weather.

Alternative form of hourglass

Alternative form of hourglass