First of all, this question is also arrived at as a result of what is written by John in the book of Revelation, chapter 20, verses 1 to 7. This passage speaks of the millennial kingdom where Jesus is going to reign for a thousand-year on earth. Well, the book of Revelation is actually more of a figurative book than a literal one. Hence, I will say, base on my research, that the millennial kingdom is figurative.
However, Peter also wrote in his book that a day is like a thousand years before God, and a thousand years is as a day before God. So, there might be more to this as this is also more of a spiritual happening, which we may not be able to grab as natural men. But the millennial is surely a figurative one, because even the Israelites are waiting for this day, and it is written that peace, joy, happiness will reign during this millennial reign of Jesus.