Let's take a look at Genesis 1 where we read the account of creation:
" In the beginning God created the heavens and the earth. 2 Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
3 And God said, “Let there be light,” and there was light. 4 God saw that the light was good, and he separated the light from the darkness. 5 God called the light “day,” and the darkness he called “night.” And there was evening, and there was morning—the first day.
6 And God said, “Let there be a vault between the waters to separate water from water.” 7 So God made the vault and separated the water under the vault from the water above it. And it was so. 8 God called the vault “sky.” And there was evening, and there was morning—the second day.
9 And God said, “Let the water under the sky be gathered to one place, and let dry ground appear.” And it was so. 10 God called the dry ground “land,” and the gathered waters he called “seas.” And God saw that it was good.
11 Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. 12 The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. 13 And there was evening, and there was morning—the third day." Genesis 1:1-13
Gen. 1:19 "And there was evening, and there was morning—the fourth day."
Gen. 1:23 "And there was evening, and there was morning—the fifth day."
Gen. 1:31 "God saw all that he had made, and it was very good. And there was evening, and there was morning—the sixth day."
The argument that is used is that the word day doesn't always mean a literal day in the Bible. I accept that, there are places that it would seem the Hebrew word for day is talking about an indefinite unit of time not a 24 hour day. But when the Bible so clearly states that there was evening and morning (and those only come once in every day but yet they do consistently come once a day) it seems quite obvious that it is saying that each day of creation was indeed just like our normal day now with an evening and a morning.
Another argument that is made is that how could God have done all that creating (and when we start truly studying the natural world we do start to realize just how much creating it really was!) in 6 normal days. Okay -- It is amazing. It is incredibly hard to comprehend. It is not truly understandable. But the thing is we have a God how can perform amazing miracles. Even if each day would have been 2 billion years - the creation that He did would still have been amazing and incomprehensible. Not matter how hard any of us tried we couldn't have done what He did no matter how long with had to do it. As far as the time that it took God to create - in the Bible it simply says that He spoke the directions and it happened. We have an amazing God!
Our time - days, months, years are based on the Sun, Moon and Earth. God planned it that was from the beginning. It says in Gen. 1:14 "And God said, “Let there be lights in the vault of the sky to separate the day from the night, and let them serve as signs to mark sacred times, and days and years, 15 and let them be lights in the vault of the sky to give light on the earth.” And it was so." God here is talking about regular Days and Years - why would He be talking about a different sort of day when we are told that it was day 1, 2,3 and so forth.
Exodus 20:11 again repeats what we have already been told that God created the earth in 6 days.
"For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy."
This is why I believe that God created the Earth in 6 literal days. What do you believe?