In Greek, there is an eight letter difference between the two phrases  (the last day = té eschaté hémera; the last days = tais eschatais hémerais). The plural affects the article, adjective, and noun. It is not a mere slip of the pen.

The literal interpretation of the last day has solid scriptural support. Daniel (12:2), Jesus (Matt. 25:31-34, 41, John 5:28-29), Paul (Acts 24:15), and John (Rev. 20:12-13) affirm one resurrection for the saved and the doomed.

This one resurrection will occur at Christ’s return according to Matthew (24:30-31), Mark (13:26-27), John (6:39, 40, 44, 54, 1 John 3:2), and Paul (1 Cor. 15:23, 52, Phil. 3:20-21, 1 Thess. 4:16-17). Jesus clearly puts His return after the tribulation and cosmic disturbances (Matt. 24:29-31).

The resurrection on the last day eliminates the notion of any earlier resurrections of deceased believers. Those brought back to life by Elijah, Elisha, Jesus, Peter, and Paul stayed in their old bodies and later died again.

Accepting one resurrection on the last day demands a spiritual explanation of the first resurrection (Rev. 20:5).

Christ made reconciliation between God and man possible by His redemption. When people—dead in their sins—are saved by Christ, the Bible depicts the event as a spiritual resurrection (John 5:24-25, Rom. 6:4-7, Eph. 2:5-6, Col. 2:13). By conversion (the first resurrection), Christians escape hell (the second death, Rev. 20:1-5).

Christ’s reign of a thousand years, known as the Millennium, must be understood in the light of these perspectives. As the eternal Son of God, Christ reigns all the time (Ps. 2, John 1:1, 14, 8:58, Matt. 28:18, Col. 1:15-17). Though He humbled Himself temporarily for our redemption, He resumed His position as Lord when He returned to heaven (Phil. 2:5-11, 1 Cor. 12:3). He reigns from heaven with the triumphant church (Rev. 4:4, 5:5-10, 20:4). The saved are made priests and kings for God (1 Pet. 2:9, Rev. 3:21, 5:10, 20:4).

Jesus repeatedly declined a political kingdom in the present world.

Satan tempted Him in vain with this kind of worldly kingdom (Matt 4:8-10). When the Galileans tried to crown Him king after He miraculously fed five thousand, He walked away (John 6:15). Pontius Pilate asked Him whether He was a king; He replied that His kingdom was not of this world (John 19:33-37). Just before Jesus' ascension, His disciples prompted Him about the restoration of the kingdom of Israel, but He shifted their focus to the spiritual kingdom that the Holy Spirit would establish in and through them (Acts 1:7-8).

In the light of Jesus’ rejection of earthly kingdoms, it seems highly unlikely that He will return to set up a political kingdom on the old earth. When He returns, He will be in a hurry to get rid of the old sinful systems and to start His marriage with His bride (Rev. 19:7).

Therefore, it seems to me in line with the entire Scripture that the Millennium is spiritual, not political, and that "first resurrection" is spiritual, not physical.

By the way, there is a vast difference between the spiritual and allegorical  interpretations of the Bible. There is a deeper spiritual meaning in Jesus’ parables, but we should not explain these allegorically by attaching arbitrary meanings to elements in the parables (such as giving names to the birds that picks up the seeds in the parable of the Sower).

This viewpoint on the resurrection and the Millennium determines the end-time scenario as listed below. God did not give us all the facts about the end-time. It is best to stick to revealed facts and leave the rest to God (Deut. 29:29).

The end-time events and circumstances will probably overlap. When a new one starts, the existing ones may proceed. They all stop with Christ’s return.

1. The signs preceding the end will occur as birth pains do—with increasing frequency and intensity: wars, famines, pestilences, earthquakes, tsunamis and storms (Matt. 24:6-7, Luke 21:25, Rev. 6:1-8, 12-17).

2. A growing apostasy will emerge in spite of worldwide evangelization (Matt. 24:12-14, 1 John 4:3, Rev. 10-11).

3. False prophets will arise, compounding a climate of deception (Matt. 24:11, 2 Thess. 2:9-12, Rev. 13).

4. Persecution of the church will increase, leading to the great tribulation (Matt. 24:9, 21, Rev. 6:9-11, 12:12-17, 13:7-8, 15, 17:6).

5. The evil trio—Antichrist, False Prophet, and Harlot—will emerge in their final form (Matt. 24:15, Rev. 13 and 17).

6. Cosmic disturbances in sun, moon, and stars will occur, drastically affecting life on earth (Matt. 24:29, Acts 2:19-20, Rev. 8, 16).

7. Christ will return in glory (Matt. 24:30-31, Acts 1:9-11, Rev. 19:11-16).

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