Completion of the church? What Scripture are you getting this from? You realize Daniel's prophecy was for Daniel's people (the Israelites) and Daniel's city (Jerusalem)....right?
Daniel 9:24
Seventy weeks are decreed for your people and your holy city to stop their transgression
Yes, but the 70th week was given to God. Only 69 weeks were given to "Daniel's people".
25 Know, therefore, and discern that seven weeks [of years] will elapse between the issuing of the decree to restore and rebuild Yerushalayim until an anointed prince comes. It will remain built for sixty-two weeks [of years], with open spaces and moats; but these will be troubled times.
26 Then, after the sixty-two weeks,
Mashiach will be cut off and have nothing. The people of a prince yet to come will destroy the city and the sanctuary, but his end will come with a flood, and desolations are decreed until the war is over.
7+62=69.
7 “To you,
Adonai, belongs righteousness; but to us today belongs shame — to us, the men of Y’hudah, the inhabitants of Yerushalayim and all Isra’el, including those nearby and those far away, throughout all the countries where you have driven them; because they broke faith with you.
8 Yes,
Adonai, shame falls on us, our kings, our leaders and our ancestors; because we sinned against you.
9 It is for
Adonai our God to show compassion and forgiveness, because we rebelled against him.
The point was not about the temple. The fullness of time was about God coming to earth. So if you take 7 years away from 490, you get 483. Only 69 weeks or 483 years was given to The Jews. The 7th week was set apart for God Himself. Jesus did not hang around after the Cross, and finish a full 7 years on earth. The Second Coming will conclude the last few years set aside for God. Daniel uses the term Adonai or Lord. The Second Coming is the Day of the Lord, mentioned in many other OT prophecies. Daniel split up 7 years given to the Lord, but used the term Messiah, and never completed the last half of the week in his prophecy.
The Messiah would be cut off mid week and have nothing. The prophecy switched back and said the temple would be destroyed, but not as part of the 70 weeks. It would just happen sometime in the middle of the Lord God’s week.
The last verse ties in with the Messiah: "He will make a strong covenant with leaders for one week [of years]. For half of the week he will put a stop to the sacrifice and the grain offering. On the wing of detestable things the desolator will come and continue until the already decreed destruction is poured out on the desolator."
The death of the Messiah put a stop to the sacrifice and the grain offering in terms of Adonai dealing with the temple. So what covenant was made with leaders that ends in desolation? It was not the binding of Satan as some claim. Why would Satan agree to that covenant? God made a covenant with Satan that would only end with Satan being bound: "On the wing of detestable things the desolator will come and continue until the already decreed destruction is poured out on the desolator." What destruction was decreed? We are not told the specifics of the covenant. It would end with the destruction of the desolation itself. The only other Scripture we have is Revelation 13. The introduction of the desolation. The 7 vials in Revelation 16 is the destruction poured out onto Satan the desolator, and the desolation, along with all who followed after Satan and the desolation. God will be on earth for 7 years, but was cut off when Messiah was cut off.
Jesus gave us a parable about the covenant with Satan, but it was longer than 7 years. It represented all time. It does explain that God sent His Son and the leaders killed Him. The finish will be when God Himself comes.
That part was left for future, but we do know that there was an application given. It was important for that time. However the parable was about Satan, not just the transfer from the Law (Temple) to Grace (the church). The covenant was not over because the last half of Daniel's 7 years given to Adonai was never completed. The covenant between God and the "leaders" will only be completed in the Second Coming when God Himself comes to earth. The destruction of the desolation will be the end of the covenant. God will pour out His wrath at that point.