Just to throw in a couple of pennies...
Dan 9:27 And he shall confirm the covenant with many for one week: and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate.
Covenant:
H1285
בּרית
berı̂yth
ber-eeth'
From H1262 (in the sense of cutting (like H1254)); a compact (because made by passing between pieces of flesh): - confederacy, [con-]feder[-ate], covenant, league.
In every case in the book of Daniel, when the word berı̂yth is used, it is used in context of the Holy Covenant...
Dan 9:4 And I prayed unto the LORD my God, and made my confession, and said, O Lord, the great and dreadful God, keeping the covenant and mercy to them that love him, and to them that keep his commandments;
Dan 11:22 And with the arms of a flood shall they be overflown from before him, and shall be broken; yea, also the prince of the covenant.
In verse 22, the prince of the covenant is taken to mean the High Priest by most scholars.
Dan 11:28 Then shall he return into his land with great riches; and his heart shall be against the holy covenant; and he shall do exploits, and return to his own land.
Dan 11:30 For the ships of Chittim shall come against him: therefore he shall be grieved, and return, and have indignation against the holy covenant: so shall he do; he shall even return, and have intelligence with them that forsake the holy covenant.
Dan 11:32 And such as do wickedly against the covenant shall he corrupt by flatteries: but the people that do know their God shall be strong, and do exploits.
The he in Dan 9:27 is Christ, who was cut off in the midst of a week, 3-1/2 years of seven and also crucified on Wednesday, the fourth day of the week.
The remaining 3-1/2 years of His week of ministry could be the 3-1/2 years of tribulation and Day of the Lord prior to His return, or it could possibly mean 3-1/2 years of ministry after His return. The heathen will not be converted instantly as shown by...
Eze 38:10 Thus saith the Lord GOD; It shall also come to pass, that at the same time shall things come into thy mind, and thou shalt think an evil thought:
Eze 38:11 And thou shalt say, I will go up to the land of unwalled villages; I will go to them that are at rest, that dwell safely, all of them dwelling without walls, and having neither bars nor gates,
This is not the same event that occurs at the end of the Millenium in Rev 20:7-9. That is probably fuel for another thread as it takes much quoting from Ezek 38 & 39 and Rev 20 to show these are different occurrences.