Night Scene. Night or nighttime is the period from sunset to sunrise in each twenty-four hours, when the Sun is below the horizon.
   The exact time when night begins and ends depends on the location and varies throughout the year. When night is considered as a period that which follows evening, it is usually considered to start around 9 pm and to last to about 5 am. Night ends with coming of morning at sunrise.
   The word can be used in a different sense as the time between bedtime and morning. The word 'night' is used as a farewell and sometimes shortened to night.
   Unlike good morning, good afternoon, and good evening, good night is not used as a greeting. Complete darkness or astronomical night is the period between astronomical dusk and astronomical dawn when the Sun is between 18 and 90 degrees below the horizon and does not illuminate the sky.
   As seen from latitudes between 48.5° and 65.7° north or south of the Equator, complete darkness does not occur around the summer solstice because although the Sun sets, it is never more than 18° below the horizon at lower culmination. The opposite of night is day. The start and end points of time for a night vary, based on factors such as season and latitude. Twilight is the period of night after sunset or before sunrise when the Sun still illuminates the sky when it is below the horizon. At any given time, one side of Earth is bathed in sunlight
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