How long is a day? Is it 24 hours? Or just when the sun is up? Or is it a longer period of time, as in “the day of the typewriter”? It turns out that the word can mean all of these things, not only in English but also in Hebrew.
Much ink and many pixels have been used in debating the meaning in Genesis 1 of the Hebrew word yom, translated “day.” However, it is not disputed that the word can be used to mean several different things. Its most generic meaning is a period of time. It also is frequently used to mean a 24-hour day or the light part of the day (as opposed to the night). It is even used to describe a lifespan, as in “All the days of Noah were nine hundred and fifty years” (Gen. 9:29).
The Bible describes God forming the earth in six yom. This could mean six 24-hour days, but according to the literal meaning of the word, it could just as easily mean six periods of time of other length. The word yom itself really does nothing to describe the length of the creation days.
English has a number of other words that could be used to mean long periods of time, such as era, epoch, age, or eon. However, the Hebrew language does not have words such as these. There are two other Hebrew words, besides yom, that are used to communicate long periods of time. The first is olam, which means “in the far distance,” in terms of either space or time. This word would not be more appropriate than yom for communicating a long period of time marked by a definite beginning and ending. The second is dor, and this is equivalent to the English word generation. It makes no sense to have generations when there are no people, so this would not be an appropriate word to use to describe periods of time preceding the creation of man.
I have often heard it argued that every other time in the Hebrew scripture where the word yom is preceded by an ordinal number (first, second, third, etc.), it takes the sense of a 24-hour day. The conclusion is that in Genesis 1, where yom is preceded by an ordinal number, it also must have the meaning of a 24-hour day. Even assuming that the premise is true (which is disputable—see Hosea 6:2), this argument is logically invalid. Let me offer an analogy.
The word job has several meanings. It can mean a task or duty, and it can also mean a position of employment. Suppose that someone were reading a book about how to find and maintain employment and that he came to a place where it said, “If you work quickly and finish your assigned tasks, then you must look for other jobs.” The reader might reason, “Every other time that the book uses the word ‘jobs’ together with the words ‘look for,’ it means a position of employment. Therefore, this book must be saying that if I finish all my assigned work for the day then I should start to seek different employment.”
Of course, this is not what the book means. It is the other meaning of job that is intended, and the presence of “look for” is simply coincidental. Similarly, there is no rule in Hebrew grammar that the presence of an ordinal number changes the meaning of the word yom. Rather, it may just be that there is no other place where the Bible has occasion to sequentially number long periods of time. It is not sufficient just to point out that the word refers to a 24-hour day in other situations in which it is used with an ordinal number. In order to make a valid argument, it must also be shown that a different word is used instead in situations in which time periods of other lengths are numbered. I have never heard this argument made. If you can show support for it, please let me know.
So we see that the word yom, translated “day” in Genesis 1, does not in itself necessarily indicate that these were 24-hour days. The word is inconclusive; with equal validity, it could indicate either 24-hour days or longer periods of time. In the next post, I will examine the phrase “there was evening and there was morning” to see what meaning it adds.