noon

Noon is the time of day when the sun is highest in the sky, marking the midpoint of the daylight period for a given location. In everyday usage, noon usually refers to 12:00 on a 12-hour clock within a time zone. The true solar noon, however, is the moment when the Sun crosses the local meridian. This moment depends on longitude and date and can differ from 12:00 by several minutes; the difference is described by the equation of time and daylight saving time in many regions.

The word noon derives from Old English non(n) or nān, from Latin nona hora, meaning the ninth hour of the daylight in the ancient system of dividing the day into hours. Through historical usage, noon came to denote the middle of the day rather than the specific ninth hour.

Across latitudes, the apparent height of the Sun at noon varies. Near the equator the Sun can be near overhead, while toward the poles it remains lower in the sky. In extreme northern or southern latitudes, the Sun may remain above the horizon for extended periods in summer or be absent in winter.

Noon also appears in cultural and practical contexts, such as noon meals and phrases like high noon, which evoke the middle of the day. Some cities historically marked noon with cannons or bells, a practice known as a noon gun.