Tyndale Open Bible Dictionary

DAY

Most literally, a period of time delimited by the earth’s rotation around its axis, such as the period between two consecutive sunrises; also, the portion of that period in which the sun is visible, the other portion being called “night.” The word “day” occurs over 2,000 times in the OT, over 350 times in the NT. The Hebrew word for “day” is used in a variety of ways, not merely in the literal sense. The Hebrew day began in the evening and continued until the following evening, a reckoning presumably based on the Torah (cf. Gn 1:14, 19). That kind of literal solar (24-hour) day is known as a civil day. Among other ancient Near Eastern nations the civil day began at different times. Greek custom agreed with that of the Hebrews; the Babylonians started their day at sunrise; the Egyptian and Roman day stretched from one midnight to the next.

Biblical Days and Weeks

Commonly recognized units of the visible (12-hour) day were morning, noonday, and evening (Ps 55:17). Those divisions were sometimes defined by terms for dawn (Jb 3:9), the heat of the day (1 Sm 11:11), noon (Gn 43:16), the cool of the day (3:8), and evening (Ru 2:17). The Hebrew phrase “between the two evenings” (Ex 12:6, rsv mg) probably referred to dusk, the dark part of twilight (Ex 16:12). Division of days into consecutive hours did not take place until the time of Christ. The closest OT approximation to such a unit was the division of the day into quarters (Neh 9:3), perhaps a counterpart of the preexilic division of the night into watches.

The ancient Hebrews did not name the days of the week other than the Sabbath. Rather, they referred to them numerically, a practice carried over into NT times (Lk 24:1). Because of the traditional Hebrew emphasis on the Sabbath, it was important for the Jews to know the exact time when the Sabbath began. The Pharisees therefore decided that the appearance of three stars following sunset would determine the Sabbath day’s beginning.

Days of Creation

Many people believe that the days mentioned in the Genesis Creation narrative were 24-hour periods. The phrase “there was evening, there was morning” is used to support that idea. That expression, however, is actually a Sumerian literary figure that pairs opposites together to describe totality. Thus “evening-morning” means a complete phase of time within the total creative cycle; it emphasizes the completeness or comprehensiveness of the process, not the specific period of time in which that process was accomplished. The totality of Creation, phase by phase, may have been thus depicted without any necessary reference to a defined time period.

Since the Sumerian civil day included only the visible (12-hour) period, a legal day of other nations was actually a “double day” (24 hours). If the early Genesis material reflects Sumerian culture, the use of “evening-morning” would preclude current concepts of a civil day and point instead to a phase or general time period.

Old Testament

In the OT, “day” frequently has a figurative meaning—for example, the “day of the Lord” (Jl 1:15; Am 5:18), the “day of trouble” (Ps 20:1), and the “day of God’s wrath” (Jb 20:28). The plural form is sometimes used to describe a king’s reign (1 Kgs 10:21) or the extent of an individual’s life (Gn 5:4; 1 Kgs 3:14; Ps 90:12). God is described in the book of Daniel as the “Ancient of Days” (Dn 7:9, 13).

In addition to the Sabbath (Gn 2:3; Ex 20:8-11), which was reserved for rest and worship, “day” was applied to the Passover celebration each spring (Ex 12:14; Lv 23:5) and the Day of Atonement (Lv 16:29-31) each autumn. As with the Sabbath, no work was performed on those occasions; prescribed religious rituals were observed.

New Testament

In the NT the use of “day” followed Semitic usage to some extent, although the four military night watches were of Greek and Roman origin. The 12-hour day of NT times was a legacy of Babylonian astronomy (cf. Jn 11:9).

In addition to the literal usage of “day,” NT authors sometimes employed it figuratively, as in such expressions as the “day of salvation” (2 Cor 6:2) and the “day of Jesus Christ” (Phil 1:6). Or they described specified periods of time, as in the “days of his Temple duties” (Lk 1:23, tlb). Special feasts mentioned include the Passover (Jn 12:1), the days of Unleavened Bread (Acts 12:3), and the Day of Pentecost (2:1).

As in the OT, the period of human life is described as days (Jn 9:4). Christians are called “children of the light and of the day” (1 Thes 5:5, NLT). Longer periods or eras are referred to as days (2 Cor 6:2; Eph 5:16; 6:13; Heb 5:7). The ominous note struck by the Hebrew prophets about a day of judgment is matched by NT stress on a day of final divine judgment when the Son of Man (Jesus) will reveal himself as Lord (Lk 17:30; Jn 6:39-44; 1 Cor 5:5; 1 Thes 5:2; 2 Pt 2:9; 3:7, 12; 1 Jn 4:17; Rv 16:14). The “day of eternity” marks that point at which time will become eternity (2 Pt 3:18, rsv). The new Jerusalem, dwelling place of God’s people, is described as a place of perpetual day (Rv 21:25).