According to Jewish thought, the timetable for the world parallels the days of the week. After the seven “days”, thought to correlate to thousand year periods of time, comes the eighth day, or the new reign of the Messiah. The seventh day, the perfect number, is the day of the Lord. The day of the Lord is mentioned many times in Scripture as a judgment call, the separation of the sheep from the goats.
"But thanks be to God! He gives us the victory through our Lord Jesus Christ."
1 Corinthians 15:57