From BiblePortal Wikipedia

American Tract Society Bible Dictionary [1]

The word hour, in Scripture, signifies one of the twelve equal parts into which each day, from sunrise to sunset, was divided, and which of course were of different lengths at different seasons of ht year,  Matthew 20:3-6   John 11:9 . This mode of dividing the day prevailed among the Jews at least after the exile, and perhaps earlier,  Daniel 3:6   4:19 . The third, sixth, and ninth hours were the appointed seasons for prayer,  Acts 2:15   3:1   10:9 . Anciently, however, the usual division of the day was into four parts, namely, the morning-the heat of the day, commencing about the middle of the forenoon-midday, and evening. In a similar manner, the Greeks appear at first to have divided the night also into three parts or watches, namely, the first watch,  Lamentations 2:19; the middle, or second watch,  Judges 7:19; and the morning, or third watch,  Exodus 14:24 . But after the Jews became subject to the Romans, they adopted the Roman manner of dividing the night into four watches, namely, the evening, or first quarter, after sunset; the midnight; cock-crowing, or third quarter, from midnight on; and the morning, or fourth quarter, including the dawn,  Matthew 14:25   Mark 6:48   13:35   Luke 12:48 . A watch in the night seems but an instant to one who spends it in slumber,  Psalm 90:4; equally short does the life of man appear in view of eternity.

Webster's Dictionary [2]

(n. pl.) Goddess of the seasons, or of the hours of the day.

Watson's Biblical & Theological Dictionary [3]

See Day .

Hawker's Poor Man's Concordance And Dictionary [4]

See Hour

Kitto's Popular Cyclopedia of Biblial Literature [5]

The ancient Hebrews, like the Greeks, were unacquainted with any other means of distinguishing the times of day than the natural divisions of morning, midday or noon, twilight, and night (;;;; ). The earliest mention of hours occurs in Daniel (;; ); and, as the Chaldeans claimed the honor of inventing this system of notation, it is most probable that it was during their residence in Babylon that the Jews became familiar with their artificial distribution of the day. At all events no trace of it occurs before the captivity of that people; while, subsequently to their return to their own land, we find the practice adopted, and, in the time of Christ, universally established, of dividing the day and night respectively into twelve equal portions . The Jewish horology, however, in common with that of other Eastern nations, had this inherent defect, that the hours, though always equal to one another, were unequal in regard to the seasons, and that, as their day was reckoned from sunrise to sunset, and not from the fixed period of noon, as with us, the twelve hours into which it was divided varied, of course, in duration according to the fluctuations of summer and winter. The mid-day, which with us is the twelfth hour, the Jews counted their sixth, while their twelfth hour did not arrive till sunset. At the equinoxes, their hours were exactly of the same length with ours, and the time from which they began to reckon their day at those seasons corresponded precisely with our six o'clock a.m.; their first hour being our seven o'clock, their third , our nine, their ninth , our three o'clock p.m. and their eleventh , our five. This equality, however, in the duration of their hours, as well as in their correspondence to ours, was disturbed as the season approached towards the summer or winter solstice. In midsummer, when sunrise in Judea takes place at five o'clock a.m., and sunset at seven p.m., the Jewish hours were a little longer than ours; and the only one of their hours which answered exactly to ours was the sixth, or twelve o'clock, while in all the rest there was a considerable difference. Their third hour was shortly before our nine, and their ninth a little after our three. In like manner, in winter, when the sun rises at seven and sets at five, the Jewish hour was proportionally shorter than ours, their third hour not occurring till a little after our nine, and their ninth a little before our three. Hence it is evident that in order to determine exactly the duration of Daniel's silence, for instance ('he was astonied one hour,' ), or the exact time when the darkness at Christ's crucifixion ended, it is necessary to ascertain the particular seasons when these incidents occurred.

In ancient times the only way of reckoning the progress of the day was by the length of the shadow—a mode of reckoning which was both contingent on the sunshine, and served only for the guidance of individuals. By what means the Jews calculated the length of their hours—whether by dialing, by the clepsydra or water-clock, or by some horological contrivance, like what was used anciently in Persia by the Romans, and which is still used in India, a servant notifying the intervals, it is now impossible to discover.

Besides these smaller hours, there was another division of the day into larger hours, with reference to the stated periods of prayer, viz. the third, sixth, and ninth hours of the day .

The night was divided into twelve equal portions or hours, in precisely the same manner as the day. The most ancient division, however, was into three watches; the first, or beginning of the watches, as it is called the middle-watch : and the morning-watch . When Judea became a province of Rome, the Roman distribution of the night into four watches was introduced [see Cockcrowing and DAY]; to which division frequent allusions occur in the New Testament (;; ), as well as to that of hours (;;;;; ).

It remains only to notice that the word hour is sometimes used in Scripture to denote some determinate season, as 'mine hour is not yet come,'; 'this is your hour, and the power of darkness,'; 'the hour is coming,'; etc.