The Bible has PLENTY of chronology . . . not year dates, but ways to figure out what the dates were!
You can read about them here:
http://wol.jw.org/en/wol/d/r1/lp-e/1200000970
In the year of 1975 --IF Adam had remained faithful & alive-- he would have reached 6,000 years of age!
So that 'the *world* of mankind that is alienated from God' IS just over 6,000 years of age!
"We know we originate with God, but,
the *whole world* is lying in the power of the wicked one."---1 John 5:19
http://wol.jw.org/en/wol/bl/r1/lp-e?q=1+John+5%3A19
"Where Is This World Headed?"
http://wol.jw.org/en/wol/d/r1/lp-e/102007123?q=will+this+world+survive&p=par
The Bible does *NOT* state how old the *earth* was at any given time, nor give any way for us to figure out how old it is. All it says about the earth in Genesis 1:1, is that the universe & the earth were in existence BEFORE the earthly creative sequences began. This is something that Bible scholars do agree upon:
"Does Science Contradict the Genesis Account?"
- When Was "the Beginning"?
- How Long Were the Creative Days?
http://wol.jw.org/en/wol/d/r1/lp-e/102006326