The proper translation of
Anno Domine (or AD for the
unwashed masses).
Indicates a time after the birth of this Christ fellow, so it would be AD 2000.
A common misconception is that it means After Death, which makes no sense, because there would be no era between the supposed birth of Christ to his crucifixion. Also, the proper form is AD 2000, rather than 2000 AD, because it would then mean 2000 The year of our lord.
Common Era is now used more often by those in protest of the Christian church.