When Adam was born exactly ?

I didn't know Adam was born, I thought he was rolled out of left over pizza dough and sneezed on by a deity. I assume you are talking about the Adam of apple and snake fame?

Well, first you'd have to prove Adam existed in order to determine which year he was born in. Furthermore, if he were born, it would disprove the Bible's account of how he came into existence. For the purpose of this post, I'll assume you meant "created". If you wanted to get hypothetical, though, it would depend on your interpretation of the Bible. If you were a literalist, he was created on the 5th day of year 1 ( or year 4006 B.C. if your using the current calendar with with the old belief that the world is 6000 or so years old ). If you are going with any other interpretation, then you're going to be hard pressed to find a date for his creation.