There are some Christians out there who are Preterist in their understanding of the 70 Weeks of Daniel including the 70th. But still Premillennial, and Futurist in their understanding of Revelation, Matthew 24 and other parts of Daniel. They believe there is no gap between the 69th and 70th Week, and that the 70 Weeks prophecy has no connection to Revelation or the End Times. They are all "Post-Trib" from what I've seen so far.
This belief itself can have different forms in how they believe the 70 Weeks are already fulfilled. The point is they believe it is the great error of most Futurists to force a 7 year time period into their understanding of Revelation. They insist Revelation and Daniel 12 all repeatedly define the time period of the End Times as 42 Months, 1260 days, Time Times and half a Time, ect.
That this time peirod happens to be half of seven years, and Daniel 9:27 happens to divide it's 70th week in half, and Daniel 12 again brings up the Abomination of Desolation in one of those time period references, is all just a coincidence.
Related to this is another view that there is a gap, but the gap is in the middle of the 70th week, not between the last two weeks. That Jesus on the Cross marks the mid-Way point of the 70th Week, not the end of the 69th as a plain reading implies.
They wouldn't consider what I pointed out above a coincidence. But they view the first half as having nothing to do with Revelation, and so would agree that all references to 3.5 years in Revelation are about the same time period. There is no coming seven year period.
Problem is, the 42 months of Revelation 11:2 and 1260 days of Revelation 12:6 can't be the same time period. In the former Israel controls The Temple, the Gentiles only have the Outer Court, but in the Latter they're hiding in The Wilderness.
There are two ways they would respond to this argument of mine.
Some would allegories 11:2, the Temple and Holy City there is The Church, not Jerusalem. And the Outer Court being Trodden Under Foot refers to either 1. Persecution, or 2. fake Christians within the Church. They argue this Holy City can't be the Same as terrestrial Jerusalem described latter as "Spiritually Sodom and Egypt". But that is always the nature of Jerusalem in the Old Testament. She constantly falls into a Sinful State , but God never ceases considering her his Holy City.
The alternative is to reject the The Woman being Israel, or at least National Israel, bringing replacement theology into it. Saying she's The Church, or part of The Church. Or keeping her as National Israel but only the believing Remnant. Such views convolute things too much.
So yes, a Seven Year time peirod can be demonstrated from Revelation alone, without turning to Daniel.
I believe Revelation 11's 3.5 year references are the first half of the 70th Week. The Seventh Trumpet marks the midway point and The Rapture, and then the 3.5 year references in Revelation 12 and 13 are the second half.
I've elaborated on this here.