The approaching end of a millennium stimulated interest in the biblical millennium. A period of 1000 years, sometimes referred to as the "messianic millennium," is mentioned three times in Revelation 20 (verses 4, 5 and 7). This millennium begins right after the return of Jesus Christ to the earth, described in Revelation 19. Many apparently have assumed there is a connection between the biblical millennium and the arrival or year 2000 on our modern calendars, but our popular calendar is irrelevant to God's timetable.
First of all, technically, this millennium doesn't end until December 31, 2000. (This also means that some people's apocalyptic expectations will run high into 2001.) More importantly, these "millenniums" are merely arbitrarily defined time spans on a man-made calendar, nothing more.
Regarding the return of Jesus Christ, the Bible never says He would return 2000 years after His birth. And this year does not mark 2000 years since His birth. It's true that when our Roman calendar was established, the counting of years was supposed to begin with the birth of Christ, but there was a sizable error in the reckoning. Jesus probably was born in 4 B.C. So the 2000 years since Christ's birth ended a few years ago. Therefore our calendars give no clue to when Christ will return.