Mt 24:29-31, Mt 24:36, Acts 1:6-7, Mt 25:31
In the Old Testament, the prophet Zechariah described the day of the Second Coming of Christ. When Christ comes, there will be riots and people will flee. Then it will be dark and neither night nor day. Then Christ, our light, comes. (Zec 14:4-7)
Zec 14:4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south. 5 And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the Lord my God shall come, and all the saints with thee. 6 And it shall come to pass in that day, that the light shall not be clear, nor dark: 7 But it shall be one day which shall be known to the Lord, not day, nor night: but it shall come to pass, that at evening time it shall be light.
Jesus said that in the last days the sun and the moon will not give their light, and the powers of heaven will be shaken. Then Jesus, the Christ, will come in the clouds. (Mt 24:29-31, Mt 25:31)
Mt 24:29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: 30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. 31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
Mt 25:31 When the Son of man shall come in his glory, and all the holy angels with him, then shall he sit upon the throne of his glory:
The last day only God knows. (Matthew 24:36, Acts 1:6-7)
Matthew 24:36 But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only.
Acts 1:6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel? 7 And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power.