Covers this 'appointed time' set by God for the coming of Christ. But... you've got to go back to the Manuscripts to discover it. Those verses there in Daniel are about the ten horned kingdom which is the same 'beast' system of Rev.13 & 17. That diverse or unique king in...

 Daniel 7:24: And the ten horns out of this kingdom are ten kings that shall arise: and another shall rise after them; and he shall be diverse from the first, and he shall subdue three kings.

 ...Is Satan as a false Messiah, and he 'will think to change times and laws'.  Properly translated from the Manuscript Aramaic that phrase means; He 'will hope to alter an appointed occasion and decree or law'. That decree or law is God's Law, His written Word, which gives the appointed or set time for Christ's return, all according to the seven signs our Lord gave us in...

Matt.24:

Mark 13:    Read All.

Luke 21:

...And in the Book of Revelation.

Therefore, this set occasion or time of Christ's return written in God's Law the Word, Satan will hope to alter by playing a spurious Messiah! This all means that God of course knew just what Satan would do in our near future, and our Father is going to allow it to come to pass. In other words, Yehovah is going to let Satan play the role of LORD, the casting part in the play he's always wanted. But it's only going to last for five months, as written in Rev.9. Well why would God let him do such a thing, that is, let Satan come to earth and play the role of Jesus Christ Messiah, hoping to fool us? Our Father is angry that His children have turned away from Him, as He won't make us love Him. And just to let us know how utterly 'sottish' (stupid) His children can be, He's bringing this false messiah to punish those who couldn’t care less about Him or His Truth. He's going to reveal that particular Message here in 2 Thess.2 very soon.

II Th 2:4   Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the Temple of God, shewing himself that he is God.

     We've heard this idea of Lucifer exalting himself upon GOD's Throne here in Isaiah 14 and in Ezek.28. So now you've got three witnesses from The Word of this event by Satan setting himself up as a false Messiah, in God's Temple, before Jesus Christ returns.
     During this earth age of flesh, where has God's earthly Temple always been?  Where did GOD say He would dwell forever?  In Jerusalem, that's where. Isn't this verse here in 2 Thess. telling us where Satan (son of perdition) is going to try to exalt himself?  That's why our Lord and Saviour told His disciples (of the future) to get out of Judea when they see the 'abomination of desolation'   Daniel spoke of standing where it (he) ought not, in Jerusalem, in the Temple of God.

II Thess 2:5   Remember ye not, that, when I was yet with you, I told you these things?
6    And now ye know what withholdeth that he might be revealed in his time.
7    For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.

     The one who is doing the withholding is the angel which has Satan bound in the pit, until he is let loose and cast down to earth, as written in Rev.12 & 13.  Since the Archangel Michael casts Satan out, he's probably the one holding Satan back now. And remember, that pit or hell is a place of separation across the 'great gulf