How long does Les think human history will be?
Human history is expected to span 7,000 years total. Since about six thousand years have already elapsed, roughly one thousand years remain, which will complete the fullness of times awaiting the human race. This final period is the dispensation of the fullness of times.
Les explains that when human history is finally brought to the full, when it winds down, he feels it is going to be 7,000 years. Since we have already come six thousand years, he concludes there is a thousand years left, which he connects with the dispensation of the fullness of times still awaiting the human race. He also emphasizes that everything begins and ends in and with God, and that God is sovereign, having made known the mystery of His will according to His good pleasure.