The day of the Lord is the 1,000 year-reign of King Jesus beginning at His second coming to this earth! This will happen after the rapture of the church, and the Tribulation period to include the Great Tribulation. The kingdom of the world, with Satan as the god of this world, will become the Millennial kingdom of King Jesus! He will come in righteousness and justice to judge and defeat the destroyers of this present world. Jesus will establish His kingdom with righteousness and perfect love. There will be Jews and Gentiles that come out of the Great Tribulation alive in their mortal bodies. He will restore the kingdom to a believing Israel with believing Gentiles among them. At the end of the Millennial kingdom, all believers will enter the Eternal kingdom to be eternally in the presence of God!