.... and, of course they claim it must be future - to us - not just future at the time of writing.
The only detailed instruction Jesus gives about his yet future coming is:
Luke 17:
33 Heaven and earth shall pass away: but my words shall not pass away. 34 And take heed to yourselves, lest at any time your hearts be overcharged with surfeiting, and drunkenness, and cares of this life, and so that day come upon you unawares. 35 For as a snare shall it come on all them that dwell on the face of the whole earth. 36 Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that shall come to pass, and to stand before the Son of man.
There's a LOT of money available to those who write books about future prophecy, & not much for those who see the explicit prophecies fulfilled in the AD 70 destruction.
Prophecy can & should be tested. John gave prophecies regarding Jesus:
And many resorted unto him, and said, John did no miracle: but all things that John spake of this man were true. John 10:41
Please read Deut. 18:15-19 regarding Jesus;
and then 20-22 regarding false prophets.
In Mat. 24, Mark 13, Luke 17 & 21 & in various last week parables & warnings, Jesus gave explicit prophecies, often with such a clear time indication that his enemies understood that he was prophesying against them. That's why they killed him. They understood the prophecies though they rejected them. And they remembered them decades later, asserting that Jesus was a false prophet. 2 Peter 3.
3 knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 4 and saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
Did those scoffers also fall asleep, "knowing" that Jesus' prophecies were false?
No! They suffered swift destruction. 2 Peter 2:1
Jesus' prophecies were understood, doubted, & challenged; & were fulfilled in detail in AD 70. While we don't have an inspired eye-witness account, the historical evidence is there.
The futurist's prophecies are worthless - they are attempts to interpret prophecy in a way that CANNOT be tested. The claim to relate the signs in the Olivet prophecies to current events has consistently failed.
Deut. 18:21 And if thou say in thine heart, How shall we know the word which the Lord hath not spoken? 22 when a prophet speaketh in the name of the Lord, if the thing follow not, nor come to pass, that is the thing which the Lord hath not spoken, but the prophet hath spoken it presumptuously: thou shalt not be afraid of him.