Midnight

n. twelve o'clock at night, 12:00 A.M.; middle of the night

Midnight is, literally, "the middle of the night." In most systems it is when one day ends and the next begins: when the date changes. Originally midnight was halfway between sunset and dawn, varying according to the seasons. Solar midnight is that time opposite of solar noon, when the sun is closest to nadir and the night is equi-distant from dusk and dawn. Due to the advent of time zones, which makes time identical across a range of meridians, and daylight saving time it rarely coincides with midnight on a clock, but can be computed on a number of websites that perform solar time calculations. Solar midnight is dependent on longitude, latitude, altitude, and time of the year rather than on a time zone.
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Noun
1. 12 o'clock at night; the middle of the night; "young children should not be allowed to stay up until midnight"
(hypernym) hour, time of day
(part-holonym) night, nighttime, dark

(n.)
The middle of the night; twelve o'clock at night.
  

(a.)
Being in, or characteristic of, the middle of the night; as, midnight studies; midnight gloom.
  

n.
آدھي رات, نيم شب, (نصف شب)