Genesis was written in Hebrew and the word for "day" is "yowm" which means "time period".
Besides, the bible is written in parables...Jesus speaking:
Mar 4:11 And he said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all [these] things are done in parables:
When you read Revelation and you see phrases like "one hour with the beast", do you really think it's speaking of one literal hour?
So Jesus arose on the third time period and not the third day? There wasn't a controversy until science proved 6 days impossible. That's when the definition broadened. For 18 hundred years yowm meant day.
I’ve always been fascinated with the concept of time, and I believe that it is our lack of understanding of it from God’s perspective which inhibits our ability to reconcile all these differences together.
I do, however, believe that God created the earth in 6 literal days and the reason for this is the following -
Exodus 20:8 Remember the sabbath day, to keep it holy.
9 Six days shalt thou labour, and do all thy work:
10 But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates:
11 For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
Here God very clearly relates His six days of work and seventh day of rest to a literal six day work week and a sabbath day of rest. Now why would He do that if not to demonstrate that the use of the word “day” - yowm in both instances, were to be taken as a literal 24 hour period? (By the way, the word yowm is used as a literal day 2008 times in scripture as opposed to 64 for general period.)
From His perspective, maybe the time it took for the information to reach earth was much longer - in fact, here is an interesting article discussing such a thing - http://aish.com/societywork/sciencenature/Age_of_the_Universe.asp)