How Long Is a Genesis “Day”?
Many consider the word “day” used in Genesis chapter 1 to mean 24 hours. However, in Genesis 1:5 God himself is said to divide day into a smaller period of time, calling just the light portion “day.” In Genesis 2:4 all the creative periods are called one “day”: “This is a history of the heavens and the earth in the time of their being created, in the day [all six creative periods] that God made earth and heaven.”
The Hebrew word yohm, translated “day,” can mean different lengths of time. Among the meanings possible, William Wilson’s Old Testament Word Studies includes the following: “A day; it is frequently put for time in general, or for a long time; a whole period under consideration . . . Day is also put for a particular season or time when any extraordinary event happens.”1 This last sentence appears to fit the creative “days,” for certainly they were periods when extraordinary events were described as happening. It also allows for periods much longer than 24 hours.
Genesis chapter 1 uses the expressions “evening” and “morning” relative to the creative periods. Does this not indicate that they were 24 hours long? Not necessarily. In some places people often refer to a man’s lifetime as his “day.” They speak of “my father’s day” or “in Shakespeare’s day.” They may divide up that lifetime “day,” saying “in the morning [or dawn] of his life” or “in the evening [or twilight] of his life.” So ‘evening and morning’ in Genesis chapter 1 does not limit the meaning to a literal 24 hours.
