a day with God is as a thousand years, and a thousand years as a day
2 Peter 3:8 IIRC. However, also IIRC, 2 Peter 3:8 is not addressing the creation account in any way. Hebrew can be written in one of two ways; narrative and poetic. The two forms are easily distinguishable by sentence structure (as I'm not a linguist, I have to take the word of the rabbis who did the study. I don't have the link on hand, but I imagine a google search could turn it up). Genesis 1 is clearly written in the narrative format and was meant to be taken literally.
Furthermore, every single time in the Bible the Hebrew word for day (yom) is used in connection with a number outside of Genesis, it has always, 100%, without fail meant a literal 24-hour period. It stands to reason that since Genesis 1 is narrative and since yom was used in connection with numbers that the writer of Genesis meant for it to be taken absolutely literally.
See Christiananswers.net
There is no middle ground with the Bible. Either God created the Earth in 6 days, or the Bible is wrong.
"Either God created the Earth in 6 days, or the Bible is wrong." Ah, yes. But I seem to recall the existence of a bible verse that refers to the "four corners" of the Earth. Was the Bible right there, too???