I doubt very much that this interpretation of Genesis 1 needs much introduction. When the topic of Creation is brought up, the first interpretation that will come to mind is most likely the 24 hour day theory. To summarize this interpretation, which is also referred to as Young Earth Creationism, this view holds that each of the days in the creation narrative of Genesis 1 is a literal 24 hour day. Everything, the earth itself, the universe, plant and animal life, and humanity, are all the result of special acts of creation by God. Proponents of this view will then appeal to the genealogies listed in the Bible to arrive at a rough estimate of the age of the earth and the universe.
One of the heavily debated topics of Genesis 1 is whether or not it is meant to be understood as presenting scientific history. In order to give some insight on the nature of the intent of Genesis 1, and whether or not it was intended to give scientific information, Gerhard von Rad had this to say:
This account of Creation is, of course, completely bound to the cosmological knowledge of its time. But it is a bad thing for the Christian expositor completely to disregard this latter as obsolete, as if the theologian has only to deal with the faith expressed in Genesis 1 and not with its view of nature. For there can be no doubt that the Creation story in the Priestly Document [that is to say, in Genesis 1] seeks to convey not merely theological, but also scientific, knowledge. It is characterized by the fact, which is difficult for us to understand, that here theological and scientific knowledge are in accord with no tension between them. The two sets of statements are not only parallel, but are interwoven in such a way that one cannot really say of any part of Genesis 1 that this particular statement is purely scientific (and therefore without importance for us) while that one is purely theological. In the scientific ideas of the time theology had found an instrument which suited it perfectly, and which it could make use of for the appropriate unfolding of certain subjects – in this case the doctrine of Creation. 
What he is saying here is that Genesis 1 was a scientific account of the origins of the universe. However, he believes that the Hebrews were wrong in their primitive understanding of scientific theory.
What is amusing is that Young Earth Creationists agree with von Rad that Genesis 1 is a scientific account, but they differ from him in that they also believe Genesis 1 to be an accurate scientific account of the origins of the universe.The question we are left with is whether or not this interpretation of Genesis 1 is warranted.
II. Support for the Twenty-Four-Hour Day Theory
From the outset, it needs to be stated that Young Earth creation is one of, if not the, most textually and theologically consistent and straight forward interpretations of Genesis 1. In fact, with regard to this truth, Intelligent Design Theorist, old earth creationist, and (I believe) theistic evolutionist, William Dembski had these points to say about Young Earth Creationism:
- “Genesis 1-3 confronts us with the problem of reconciling natural history (chronos) with the order of creation (kairos). To this problem, young-earth creationism offers a straightforward solution: it equates natural history with the order of creation. This solution is, to be sure, theologically neat.” 
- “When asked what’s riding on a young earth, proponents of this position cite Rom. 5.12, which speaks of death as a consequence of human sin. Sure, one can try to make an exegetical argument that passages like Rom. 5.12 speak strictly about human death. But young-earth creationists have the stronger case here, both exegetically and theologically, in interpreting such passages as speaking about death and corruption generally and not just about human death. Without a young earth (i.e., and earth created in six 24-hour days and spanning a history of only a few thousand years), how can natural evil be traced back to human sin?” 
So after reading these quotes, what makes the young earth position so attractive?
1. Argument from the word “Day.” – Some have said that the word “yom,” meaning “day” in the Hebrew language, is always used in the sense of a 24 hour solar day. This argument has fallen out of favor among young earth creationists. More recently however, more emphasis has been given to the word yom being preceded by an ordinal number (ordinal numbers are numbers used to describe order, such as first day, or second day). On this subject, Charles Ryrie says that “The word ‘day’ when used with a numerical adjective in the Pentateuch, always indicates a solar day… To be sure, the word ‘day’ is used in several senses, but with the numeral or ordinal it only means a solar day (Gen. 1.5, 8, 13, 19, 23, 31).
2. The phrase “evening and morning.” – Having the phrase “evening and morning” attached to the days of creation lend support to the claim they are 24 hour days. This phrase carries with it references to specific times and events of a day, what we normally think of as markers for the beginning and ending of a normal solar day. “To suggest any form of a day age concept involves denying the normal meaning of these words.” 
3. The use of the creation week as the basis for the six day work week culminating in the Sabbath day of rest in Exodus 20.8-11. – This passage in Exodus (and also in 31.17) is the command by God to the Israelites to obey the Sabbath. They were to follow the pattern set forth by God of working for six days, and then resting on the seventh. This is good evidence that the creation days were 24 hour days because the literal seven day week that the Israelites observed is presented in a parallel fashion with the seven day week of creation.
Six days you shall labor, and do all your work, but the seventh day is a Sabbath to the LORD your God… For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day.
4. The assumption of the historicity of Adam and Eve by other biblical authors. – Throughout the entire Bible, whenever the biblical authors make mention of Adam or Eve, they are always assumed to be real, literal, historical figures. They are not merely allegories used to depict general truths about humanity. Luke tracked the genealogy of Jesus all the way back to Adam (Lk. 3.38), and Paul taught that all of humanity is born into the family/realm of our initial representative before God, Adam, who was a foreshadowing of the perfect Adam, Jesus Christ (Rom. 5.15-21). Of course, we also cannot write off the central figure of the creation narrative as non-literal, namely, God Himself.
III. Conclusion on the Strengths of the Twenty-Four-Hour Day Theory
All of these points taken together present a strong case for a literal interpretation of Genesis 1. When it comes to assessing the different interpretations, the literal one is most certainly a live option that needs to be considered. That being said, it now needs to be asked: what are the weaknesses of the 24 hour day view? That will be the topic of my next post.
 Gerhard von Rad, Old Testament Theology, Volume 1. 148. Qtd. in Defenders Series 2: Creation and Evolution Pt. 2 Transcript. By William Lane Craig.
 William A. Dembksi. The End of Christianity: Finding a Good God in an Evil World. 126.
 ibid. 48-49.
 Charles Ryrie. Basic Theology. 211.
Paul Enns. The Moody Handbook of Theology: Revised and Expanded. 315.