The Jews reckoned the day from sunset to sunset (Lev. 23:32). It was originally divided into three parts (Ps. 55:17). “The heat of the day” (1 Sam. 11:11; Neh. 7:3) was at our nine o’clock, and “the cool of the day” just before sunset (Gen. 3:8). Before the Captivity the Jews divided the night into three watches, (1) from sunset to midnight (Lam. 2:19); (2) from midnight till the cock-crowing (Judg. 7:19); and (3) from the cock-crowing till sunrise (Ex. 14:24). In the New Testament the division of the Greeks and Romans into four watches was adopted (Mark 13:35). (See WATCHES.)

The division of the day by hours is first mentioned in Dan. 3:6, 15; 4:19; 5:5. This mode of reckoning was borrowed from the Chaldeans. The reckoning of twelve hours was from sunrise to sunset, and accordingly the hours were of variable length (John 11:9).

The word “day” sometimes signifies an indefinite time (Gen. 2:4; Isa. 22:5; Heb. 3:8, etc.). In Job 3:1 it denotes a birthday, and in Isa. 2:12, Acts 17:31, and 2 Tim. 1:18, the great day of final judgment.

The variable length of the natural day at different seasons led in the very earliest times to the adoption of the civil day (or one revolution of the sun) as a standard of time. The Hebrews reckoned the day from evening to evening, (Leviticus 23:32) deriving it from (Genesis 1:5) “the evening and the morning were the first day.” The Jews are supposed, like the modern Arabs, to have adopted from an early period minute specifications of the parts of the natural day. Roughly, indeed, they were content to divide it into “morning, evening and noonday,” (Psalms 55:17) but when they wished for greater accuracy they pointed to six unequal parts, each of which was again subdivided. These are held to have been—