In 539 BC, Cyrus the Great conquered Babylon and rules Media-Persia. Daniel prays three weeks and is given the final vision of Media-Persia and Greece. Then Daniel jumps forward to the rule of Antichrist during the Tribulation.

The End Times is the period after the cross: Church Age, Tribulation and Millennium. The Tribulation is not the end of the world and not the end of time but the end of human rule. All nations fall so Jesus Christ reigns. The Tribulation is a time of trouble, the worst seven years of human history. Once all Christians are removed during the Rapture, humanity follows Satan and begins their full assault against God and God's people (Revelation 13:7). God judges the rebellious that refuse His mercy and grace, steal His land, slaughter His people and challenge His authority over the earth.

However, God is merciful (Exodus 34:6). The Tribulation is the final opportunity for people to repent and turn to God for salvation. Since the beginning of time, God's plan has always been redemption of humanity. During the Tribulation, He uses two witnesses (Revelation 11:3, 5-6), 144,000 Jewish evangelists (Revelation 7:3-4) and Tribulation Saints (Revelation 14:12) to share the message of good news. Michael the Archangel leads the heavenly realm to protect God's people.

At that time shall Michael stand up, the great prince which stands for the children of your people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time your people shall be delivered, every one that shall be found written in the book (Daniel 12:1).

God judges people's actions according to the books. The four books are the righteous (Lamb's Book of Life), wicked, intermediates and remembrance or deeds (Revelation 20:12). Man is weighed in the balances compared to the righteousness of God. Those that believe in Christ are written in the Book of Life and are judged for reward and promotion (Matthew 25:21, 2 Corinthians 5:10). Tribulation Saints that are martyred, reigns with Christ (Revelation 20:4). The unrepentant and those who follow Antichrist are judged by their works written in the book of deeds (Revelation 20:15).

Many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. And they that are wise shall shine as the brightness of the firmament; and they that turn many to righteousness as the stars for ever and ever (Daniel 12:2-3).

Daniel was told to seal the book. A practical reason to seal the book was to prove a prophet's message was from God. Later, the prophet's writings were unsealed and tested against truth. This guarded against false prophets who wrote history and then claimed it was prophecy. John was told not to seal Revelation because the End Times has started with the churches (Revelation 22:10).

The time of the end occurs when travel and knowledge increases. In the last 120 years, transportation changed from walking and horseback to cars and airplanes. In 1900, knowledge doubled every hundred years but now computers make knowledge doubles every year. Artificial intelligence is advancing knowledge even further. The wise will understand, the Saints will be tried and purified but the wicked will be wicked.

But you, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased (Daniel 12:4).
I heard, but I understood not: then said I, O my Lord, what shall be the end of these things? And he said, Go your way, Daniel: for the words are closed up and sealed till the time of the end. Many shall be purified, and made white, and tried; but the wicked shall do wickedly: and none of the wicked shall understand; but the wise shall understand. (Daniel 12:8-9, 10).

The Tribulation lasts seven years (Daniel 9:27). The first 3½ years is a time that the world chooses sides as there are 2 witnesses and 144,000 evangelist with a backdrop of World War III before the Antichrist rules. When divided in half, there are 3½ years (Daniel 7:25, 12:7, Revelation 12:14) or 42 months (Revelation 11:2, Revelation 13:5) or 1260 days (Revelation 11:3, 12:6). In Daniel's vision, he sees two along the bank of the river. How long shall it be to the end? Time, times and an half or one year plus two years plus an half year which is three and a half years.

Then I Daniel looked, and, behold, there stood two, the one on this side of the bank of the river, and the other on that side of the bank of the river. And one said to the man clothed in linen, which was upon the waters of the river, How long shall it be to the end of these wonders? And I heard the man clothed in linen, which was upon the waters of the river, when he held up his right hand and his left hand unto heaven, and swore by him that lives for ever that it shall be for a time, times, and an half; and when he shall have accomplished to scatter the power of the holy people, all these things shall be finished (Daniel 12:5-6, 7).

There are three periods of days mentioned: 1260, 1290, 1335. The second half of the Tribulation is called the Great Tribulation. With the power of Satan, Antichrist rules the world for 1260 days (Revelation 13:5). The time of mourning for the dead is thirty days (Deuteronomy 34:8). It takes forty-five days to judge the nations (Matthew 25:32). Jesus Christ's Second Coming is on the 10th of Tishri (Atonement). Thirty days later is the 10th of Heshvan and forty-five days more is the 25th. Those who persevere through the Tribulation and judgment of the nations, enter the Millennium on Hanukkah.

<  1260 Days = Antichrist Rule    Great Tribulation
<  1290 Days = 30 Days               Mourning for the Dead
<  1335 Days = 45 Days               Judgment of the Nations
    1335 Days                                 Hanukkah

And from the time that the daily sacrifice shall be taken away, and the abomination that makes desolate set up, there shall be a thousand two hundred and ninety days. Blessed is he that waits, and cometh to the thousand three hundred and thirty-five days. (Daniel 12:11-12).

At the end of the last vision, Daniel ends the book with more questions. But the angel says to Daniel to go your way and rest. Throughout Daniel's life, he was faithful to God, used his position in Babylonian captivity to protect the Jewish people and was found to be a true prophet of God. Daniel wrote the prophecies of God for us to know and understand the Gentile empires and End Times.

Go your way till the end: for you shall rest, and stand in your lot at the end of the days (Daniel 12:13).

References: 21st Century Revelation: World Wars, Iraq Wars & End Wars Chapter 8 - Prophecy Fulfilled, Appendix C - Prophecy Fulfilled, Chapter 13, Minor Feasts, Major Events, 21st Century View, Tribulation Timeline, Covenant, Tribulation, Revelation, Unholy Trinity, World War III, World War IV, World War V, Second Coming, Millennium