Night or nighttime is the period of time between the sunset and the sunrise when the Sun is below the horizon. This occurs after dusk. The opposite of night is day (or "daytime" to distinguish it from "day" as used for a 24-hour period). The start and end points of time of a night vary based on factors such as season, latitude, longitude and timezone.

At any given time, one side of the planet Earth is bathed in light from the Sun (the daytime) and the other side of the Earth is in the shadow caused by the Earth blocking the light of the sun. This shadow is what we call the darkness of night. Natural illumination is still provided by a combination of moonlight, planetary light, starlight, diffuse zodiacal light, gegenschein, and airglow. In some circumstances, bioluminescence, aurorae and lightning can provide some illumination. The glow provided by artificial illumination is sometimes referred to as light pollution because it can interfere with observational astronomy and ecosystems.

Read more about Night:  Duration and Geography, On Other Celestial Bodies, Impact On Life

Famous quotes containing the word night:

    Where is the nightingale,
    in what myrrh-wood and dim?
    ah, let the night come back,
    for we would conjure back
    all that enchanted him,
    all that enchanted him.
    Hilda Doolittle (1886–1961)

    So tedious is this day
    As is the night before some festival
    To an impatient child that hath new robes
    And may not wear them.
    William Shakespeare (1564–1616)

    This night has been so strange that it seemed
    As if the hair stood up on my head.
    From going-down of the sun I have dreamed
    That women laughing, or timid or wild,
    In rustle of lace or silken stuff,
    Climbed up my creaking stair.
    William Butler Yeats (1865–1939)