score:4
I believe the only possible answer to this question, that all Christians can agree with is:
For you*, Christ cannot possibly return any sooner than right now.
All anyone can know is that Christ has not yet come, but that he will come in the future. That may be in five seconds, or in 50,000 years. Biblical prophecies are not specific enough that it is possible to come to any consensus as to what specific historical events they might refer to.
The fact that people have been making specific predictions of the second coming for centuries should be the first clue that not everyone will agree there are still specific events that "must" occur before the second coming.
* Some believe that Christ's second coming is referring to a person's individual judgment at the time of death. In that view, the second coming has already occurred for everyone who has died, and is still in the future for everyone else.
Upvote:2
I'm not sure what the lower limit would be on the date, but we do have some passages in Scripture which tell us what events must take place before Christ's return. For example:
Now we request you, brethren, with regard to the coming of our Lord Jesus Christ and our gathering together to Him, that you not be quickly shaken from your composure or be disturbed either by a spirit or a message or a letter as if from us, to the effect that the day of the Lord has come. Let no one in any way deceive you, for it will not come unless the apostasy comes first, and the man of lawlessness is revealed, the son of destruction, who opposes and exalts himself above every so-called god or object of worship, so that he takes his seat in the temple of God, displaying himself as being God. -2 Thessalonians 2:1-4
This is generally taken to be referring to the Antichrist.
Jesus also talked about a number of things in Matthew 24 that are often considered "end-times" events. There are many interpretations for many of these prophecies, but this one seems pretty clear regardless of where you stand on eschatology:
“But immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from the sky, and the powers of the heavens will be shaken. And then the sign of the Son of Man will appear in the sky ... and they will see the Son of Man coming on the clouds of the sky with power and great glory. And He will send forth His angels with a great trumpet and they will gather together His elect from the four winds, from one end of the sky to the other. -Matthew 24:29-31
Upvote:2
The original context of "No man knows the day or the hour" was exactly so that people would not think Christ's return was far off.
If a man knew when the strongman was coming to break into the house...
Also, Jesus told other parables to warn people that they needed to be ready: The parable of the foolish virgins (the one where 5 of the virgins use up all their oil) is but one example.
As such, it is actually just as counter biblical to say "Christ cannot return until __" as it is to say, he will be here on Tuesday.