How do Daniel and Revelation fit together?

The book of Daniel and the book of Revelation are directly tied together through the image of a sealed book. Daniel received revelations about the time of trouble at the end and about the resurrection of the dead, but he was told, "shut up the words, and seal the book, even to the time of the end." This meant that what Daniel saw concerning the last days was concealed from the world until God's appointed time arrived.

That appointed time came around A.D. 96, when John received the same kind of revelation concerning the end, but with far greater detail than Daniel had been given. In Revelation 5:1, John sees "a book written within and on the backside, sealed with seven seals" in the right hand of God. This is understood to be the same sealed revelation Daniel was told to close up, now appearing in heaven, ready to be opened. In other words, before Revelation ever existed as a book in our Bibles, its contents were already sealed in God's hand, and Daniel's sealing of his own scroll pointed forward to this heavenly book.

Specifically, that sealed book in God's hand corresponds to what is now Revelation chapters 6 through 22, the part of Revelation that unfolds "the things which shall be hereafter." So Daniel's prophecy and John's revelation are two pieces of one continuous disclosure from God: Daniel was shown the end times and told to seal it up, and John was later shown the same realities in far greater fullness, given the task of writing it all down and sending it to the churches, so that what had been hidden could finally be revealed to the world.