Genesis 1 describes the vision Moses received on the Mount Sion .It lasted literal 7 days of 40 days Moses spent on the mount.
Harold Camping of the http://www.familyradio.com who is proclaiming May,21,2011 as the time of Jesus' return calculated by studying the Bible creation took place in 11013 BC so the world exist now about 13022 years .He takes the 7 days in Genesis as literal days of creation which is a horrible misunderstanding of the Bible.
The Watchtower doesn't realize that those 7 days in Genesis 1 are 7 days from the time Moses lived and stayed on the mountain !
But they got some 49 000 years for world's existence.
If we consider the fact that God can create a 100-year old body in seconds then we can get into a vary precarious situation.
We can see the universe ,say, 100 billion years old as we study and examine it scientifically but it might have been created in much shorter time .
God could create this universe in one year but it looks like it is 15 billion years old .
But we can explore the possibility what if the creation took so long as the science says knowing now that those 7 days in Genesis are the time God was showing Moses ( for 7 literal days ) how He was creating the world .
The best solution based on the Bible seems to be this :
6 days x 7000 years x 360 days in a prophetic year x 360 days in a prophetic year = over 15 billion years.
1/6 of that is 2.5 billion years for the age of the earth .
Now ,check these data with what the scientists say about the age of the universe and the earth.