There is so much debate on the Daniel passages with so many question, and one can go in several directions depending on which path one takes with certain statements.
Who is the "anointed" is in verse 25 and 26, the same anointed one in both verses or different anointed ones?
Cyrus, who was a major component of the restoration of the city and temple, and he is specifically called an "anointed", so is he one mentioned in Daniel?
Does the 70 weeks begin after Daniel got this message, or did it begin with the Babylonian attack on Jerusalem?
Are the 70 weeks successive or does one insert a gap in there someplace?
Whatever one chooses to be their answer to any of the questions will determine how they proceed with the other questions.
And many have proposed how they answer each using scripture and come up with different conclusions.
Daniel 9:24-27 LEB
(24) "Seventy weeks is decreed for your people and for your holy city, to put an end to the transgression and to seal up sin and to make atonement for guilt and to bring in everlasting righteousness and to seal vision and prophet and to anoint the most holy place.
(25) And you must know and you must understand that from the time of the going out of the word to restore and build Jerusalem until an anointed one—a leader—will be seven weeks and sixty-two weeks; it will be restored and will be built with streets and a moat, but in a time of oppression.
(26) "And after the sixty and two weeks an anointed one shall be cut off, and he shall have nothing, and the people of the coming leader will destroy the city and the sanctuary, and its end will be with the flood and on to the end there shall be war; these desolations are determined.
(27) And he will make a strong covenant with the many for one week, but in half of the week he will let cease sacrifice and offering and in its place a desolating abomination comes even until the determined complete destruction is poured out on the desolator."
The thing about their "tribulation" being a 7 year period is suspect because no where in scripture does "seven" and "tribulation" appear together.
Doesn't automatically mean their tribulation isn't for 7 years, but doesn't automatically mean it is either.
Just because 3 1/2 years is mentioned two times does not necessarily mean they follow each other in succession (ie. they could overlap or have a gap between them, so we can't automatically assume they are a successive 7 years).