The Millennium is when Christ returns and rules the Earth for 1000 years. Pre-millennialists believe Christ will return before the 1000 years.
Post-millennialists believe Christ will return after the 1000 years.
Amillennialists don't believe in it at all.
and Pan-millennialists believe that no one can know the future, but that everything will all pan out in the long run according to God's will and God's own time table.
Waste of time to argue this interpretation of scripture. We should be concerning ourselves with what and how can we serve God.