The date of Adam's creation is unknown, obviously. There were no effective calendars in the Garden of Eden. The description of what happened there may be nothing more than many tens of millennia distilled down into a few paragraphs.
Atheists are trying to destroy the Bible by adding to it.
The Jews count the beginning of the world 5779 years ago... but, since they don't reject education it doesn't seem to trip them up..
The creation stories both from Israel and Judah are pretty specific about the morning and the night of a day.