"Back in the Day"

[Boatti, Stephen]

        I'm new to the list, so I don't know if this has been discussed.

        I hear and read "back in the day" more and more often, meaning "back
when" or "back in the old days." I first noticed it in speech  2 or 3 years
ago among my son's college-age friends. One if his friends is
African-American and I thought it might have originated with that group.
Recently I've seen it in the NY Times and elsewhere. Just the other day it
was used in the Times's article about the residents of a block in Harlem,
first in quoting a resident, then used by the reporter himself in the story.
Any ideas as to its origin?


                                Steve