When I've heard Midtrib explain it they mean exact middle of the 70th week, though I think not every person who calls themselves Mid Trib thinks it's actually at the midpoint of the 70th week, they likely just mean they believe the rapture will be during the 70th week not at the beginning or the end, likely mislabeled pre-wrath which also holds its rapture during the 70th week, usually at the 6th seal though some who would call themselves pre-wrath like Joel Richardson place it at the 7th trumpet. In both of those cases it could be mistaken as "mid trib" if they don't know what pre-wrath means.
Pretrib considers the entire 70th week "the 7 year tribulation" and that's why they place their position before the entire 7 years. Because in their minds they have considered the entire 70th week all God's wrath.
Post trib usually also tends to lump the entire 70th week as "the tribulation", but their position on the wrath of God is different, they'll claim that the trumpets and bowls are tribulation, not the wrath of God (ignoring what Revelation 6:17 says and Revelation 15 says about the bowls). For them, generally they will consider the trumpets and bowls "tribulation" or "judgements" but not the wrath of God, and then they will consider the wrath of God to ONLY be Armageddon at the very end (in order to not contradict 1 Thessalonians 5:9), and of course, there's the hybrid position between pre-wrath and post trib where they'll understand that the bowls are the wrath of God so they'll put Jesus returning at the 7th trumpet and just call the trumpets "tribulation" and not wrath. Dalton Thomas, who's Joel Richardson's collaborator will agree with that position but refers to himself as posttrib where Joel Richardson will consider himself pre-wrath and hold the 7th trumpet position.
Midtrib as far as I know also considers the entire 70th week as "the tribulation", that's the one I just don't understand at all because nothing in scripture suggests it even misinterpreted as far as I can tell.
Pre wrath is as far as I know the only position that consistently does not consider the entire 70th week "the tribulation" though they may use that term to communicate with other people who most likely have a different position. Pre wrath will consider the first half to be "birth pains" at most or even a false messianic period of peace (if they place the first 4 seals as happening before the 70th week which I lean towards), and the period of time after the abomination of desolation until the 6th seal "Great Tribulation" though they will not make it go the entire 42 months as pos trib will, and then after the 6th seal as "the wrath of God"
I agree that labels can be confusing and misleading. But let's look at the verses themselves.
In Matthew 24, Jesus says he comes like a thief in the night. In 1Thessalonians5, the beginning of the day of the Lord begins like a thief in the night.
Condition of the world at that time in both Matthew 24 and 1Thessalonians5, business as normal - the world not in stress. Marrying and giving in marriages. The world saying peace and safety.
-------------------------------------------------------
The most well known rapture/resurrection verses are 1Thessalonians4:15-18. Ending with comfort one another with these words.
Then, if we take notice, Paul in 1Thessalononians5, tells when the rapture/resurrection will take place, as he continues writing.
First, peace and safety, suddenly shattered by the beginning of the day of the Lord - like a thief in the night. Remember in Matthew 24, Jesus said much the same, business as usual, and his coming like a thief in the night.
In 1Thessalonians5:9, Paul says that we are not appointed to wrath - implied to take place when the day of the Lord begins - but unto Salvation. Our salvation is complete with the redemption of our bodies. Our souls have already been redeemed when we embraced Jesus as our savior.
In 1Thessalonians5:10, whether we are wake or sleep - just as he said before in 1Thessalonians4:15-18, the dead in Christ and the living in Christ, we should live together with Jesus. Jesus who shall come for us and take us to heaven where He has prepared mansions.
And finally in 1Thessalonians5:11, comfort ourselves together - same sentiment to end 1Thessalonians4:15-18.
---------------------------------------------------------------------------------------
So two questions arise:
1. What induces the world to be saying peace and safety? Answer: the world thinks it has entered the messianic age, promoted by the Jews who will have mistakenly embraced the Antichrist as their messiah, and him anointed the King of Israel.
2. What triggers the beginning of the day of Lord? Answer: When said thought to be messiah, reveals his true colors, as the man of sin, by going into the temple, sitting, claiming to have achieved God-hood. Sometime, around three years (not the exact mid-point) into the 70th week (we don't have enough information to say exactly. But we do have enough information to make a good approximation of around 3 years).
-------------------------------------------------------------------------------------
So when will the rapture occur ? It could occur today, but it must occur before the act of the Antichrist, sometime around three years into the 70th week.
I do get frustrated when you persistently promote a 'rapture/ resurrection event', before Jesus Returns, without any scriptural support.