Hour

The hour (common symbol: h or hr) is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds. It is approximately 1/24 of a mean solar day.

An hour in the Universal Coordinated Time (UTC) time standard can include a negative or positive leap second, and may therefore have a duration of 3,599 or 3,601 seconds for adjustment purposes.

Although it is not a standard defined by the International System of Units, the hour is a unit accepted for use with SI, represented by the symbol h.

Read more about Hour:  Etymology, History, Counting Hours, Derived Measures and Applications

Famous quotes containing the word hour:

    twenty centuries of stony sleep
    Were vexed to nightmare by a rocking cradle,
    And what rough beast, its hour come round at last,
    Slouches towards Bethlehem to be born?
    William Butler Yeats (1865–1939)

    Now the hedgerow
    Is blanched for an hour with transitory blossom
    Of snow, a bloom more sudden
    Than that of summer,
    —T.S. (Thomas Stearns)

    A day for toil, an hour for sport,
    But for a friend is life too short.
    Ralph Waldo Emerson (1803–1882)