One thing I've been thinking about lately in regards to this is interesting, and I'd like to get some feedback on it.
Gen. 1:1 (NASB) "In the beginning God created the heavens and the earth."
Ok, so God created the heavens and the earth.
Gen. 1:2 (NASB) "The earth was formless and void, and darkness was over the surface of the deep, and the Spirit of God was moving over the surface of the waters."
Ok, so the earth at this point is seemlingly nothing but water at this point. The creation account continues with the 6 day account next in verse 3. Now I know that this perhaps doesn't have anything to do with your question about weather or not they were actually 24 hour periods, which I see no evidence otherwise, but it wouldn't be unreasonable to think that the time between when God created the heavens and the earth and when He started the 6 days could have been any length...from just a moment to a thousand years. Granted this is just speculation, but its there, and it was just something I have been thinking about lately, so I thought I'd share.
