The Hebrew word יום (yowm) being translated to “days” within Genesis can mean “day” or “time” or “year.” It can also mean a “general time period” according to the lexicon.
A day to a human is basically one rotation of the sun around the planet. What is a day to God? As Albert Einstein described in his famous Theory of Relativity, time is relative to the observer of that time, and the observer's position is relative to whichever moving object the observer is positioned on.
However, God is above and beyond time and physical space, and He controls these elements. God's universe is the spiritual dimension, where time does not exist. Time is a specification of the physical world, because the physical world is a temporary manifestation: The physical world has a beginning and an end, while God does not have a beginning or an end.
God is ageless. This is why depictions of God as an old man with a long flowing beard - as da Vinci pictured Him - are incorrect. God is the most beautiful, and ever-youthful being. He never gets old, and He never dies.
God is never subject to or limited by time or space.
Scientific evidence has shown that the creative process of the physical universe took millions if not billions of human years.
This indicates that a "day" with respect to God's creative efforts is a relative expression. A "day" in this respect could be 100 million years. It could be 250 million years or a billion years long.
It doesn't really matter. The meaning of Genesis is that the creative process of assembling the physical universe was a gradual, stepped process governed by God. God didn't just say "poof" and the whole thing was done. As Genesis clearly states, He created the elements first, which included the elements of earth, water, gas, heat, space and time. Then He created light. Then He created living organisms, from the most simplest first. Living organisms were programmed in such a way that as they "multiplied," they evolved. This was built into their genetic code, just as a software program is coded into a computer.
We know from archaeological research that this process of evolution did not take place in six human days. It took place over millions of years. The other elements of the physical universe are a lot older. We know this too. Are we to disregard science?
The only conclusion is that the "day" being discussed here is allegorical. Consider who the audience is. Consider just how little humans know about the physical universe even now. Now consider how little humans knew about the universe thousands of years ago, as the knowledge of Genesis was handed down from teacher to student over many generations. This was handed down first through oral tradition, before it was finally put into written form.
The information in Genesis is allegorical and it has always been understood as allegorical by those humbly passing it down. What does allegorical mean? Allegorical means that the information given in the text contains symbolic elements that provide a broader understanding.
Let's say, for example, that a mother has to answer her child who is asking why daddy has to leave every morning. Will she tell the child that Daddy is a stock analyst who studies the stock market and the financials of different companies and writes reports for the investment bank he works for? The child will be lost at the word "stock."
The mother will most definitely simplify the situation, and tell the child that daddy is going to a big building so he can bring home some money for their family to buy food. Or something like that. The mother will use a big dose of allegory as she tries to describe where daddy is going in a way the child will understand.
Genesis is the same way. Its language was aimed at an audience that was very simple and lived basic lives that revolved around survival and the basic necessities. These folks had little understanding of solar systems, galaxies, andromedas, red stars and so on. They had no idea what a bacteria was. They did not know what a cell was.
So the intended audience of Genesis could be categorized as less technically educated than modern humans, but they were wiser in many other ways. Their ability to understand the allegorical nature of Genesis was obviously stronger, however.
In other words, they didn't argue about whether God really created the physical universe in six human days or not. Do we see Moses debating with his students about this? No.
The central meaning of Genesis is that the physical universe was not an accidental event. It was a programmed event. It was planned. It was designed. The complexity of DNA alone should tell us that. Scientists have been calculating the chances that the complexity of DNA alone could have taken place by chance. The number is gigantic. It is about one chance out of 3 with about three thousand zeros behind the three. The chance is so small that it is practically no chance at all.
Furthermore, we can see around us that this universe is not chaotic. A chaotic, random universe would not display connected events. One event would not cause another event. Yet we see in this universe that every event is connected to another event. This scientific observation is often termed "cause and effect." For every effect there is a cause. This means that the universe is not chaotic or random. It means that nothing in the universe takes place randomly, because every event that has taken place is connected to its cause.
If all events are connected to causes, this not only means there is no chaos and no randomness. It also means that there is a design to the physical universe. It means that there was an original cause, and that original cause began the process with a design and purpose. That Original Cause is God.
And since the physical universe is complete with living beings - individual personalities - we know that the Original Cause also must contain an original personality. In other words, God is a Person. He is not a vague force. He is not a particle. He is a Person with a will and objectives.
The physical universe displays functionality and design. This functionality serves to teach us. Throughout our lives we are presented with consequences to our decisions and actions. Every act has a consequence. Why? To teach us.
Such a universe designed to teach through consequences could only come from a Person with the intention to teach.
And what is the subject that the world's consequences serve to teach us? It teaches us about how we treat others: It teaches us about love. Why? Because God created the physical world as a place of rehabilitation. A place where we could re-develop something we lost:
Our relationship of love and loving service with Him.