The "last day" is a period of time just as "the day of the LORD" is a period of time. Neither of these are simply 24 hour days.
Getting back to the question, after the Rapture only those who had not already rejected the Gospel and rejected Christ will have a chance to be saved. And here is the reason why: Even him [the Antichrist], whose coming is after the working of Satan with all power and signs and lying wonders, And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. And for this cause God shall send them strong delusion, that they should believe a lie: That they all might be damned who believed not the truth, but had pleasure in unrighteousness. (2 Thess 2:9-12)
WHAT?
THAT ISN'T HOW THE ORIGINAL TEXTS PUT IT SO I DON'T KNOW HOW YOU COULD.
1
We implore
2065
make an earnest request by someone from a preferred position (Such requesting receives special consideration because of the special relationship involved).
now you brothers
by
5228
on behalf of, for the sake of, concerning
the coming
3952
a presence, a coming an arrival, advent,
arrive to enter into a situation especially the arrival of the owner who alone can deal with a situation, the personal presence, the future visible return from heaven of Jesus
of the Lord of us Jesus Christ and our
gathering together
1997 episynagoge - a specific grouping together that fulfills the specific purpose of the gathering together
FROM EPISUNAGO - a complete collection
unto Him
2
for not quickly to be shaken you in mind nor to be troubled neither by spirit nor by word nor by letter as if by us as that IS PRESENT the day of the Lord
3
No one you should deceive in not one way because if not
shall have come
2064 to come, go
to come into being, arise, come forth, show itself, find place or influence:
to come from one place into another and used both of persons arriving and of those returning, appear, enter,
the apostasy
646
defection, revolt
(FROM APHISTEMI 'LEAVE, DEPART'
which is derived from 575 apo
'away from' and 2476 histemi, 'stand')
properly departure
(IMPLYING DESERTION) literally
'a leaving from a previous standing'
a falling away from the true religion
defection from the true religion
apostasy
Feminine of the same as apostasion defection from truth, forsake
647 apostasion
a forsaking, specifically DIVORCE
repudiation, divorce (bill of divorce)
first and
shall have been revealed
601 apokalupto to uncover, reveal
passages of persons, previously concealed, making their appearance in public: of Christ, who will return from heaven where he is now hidden (Colossians 3:3) to the earth, Luke 17:30; of Anti-christ, 2 Thessalonians 2:3, 6, 8.
the man of lawlessness the son of destruction
4
the opposing and exalting himself above every so-called god or object of worship so as for him in the temple of God to sit down setting forth he himself that is God
5
Not do you remember that YET being with you, these things I was saying to you?
6
And now that which is restraining you know (as just shown us, the Apostasy and Satan doing his thing is what is holding back the RETURN OF CHRIST AND OUR GATHERING TO HIM)
for to be revealed him in his time
(SATAN will be revealed in his time and
only after THAT is it POSSIBLE for the Lord to return. THE Lord can not come before Satan is revealed
and Satan will not be REVEALED until AFTER he has sat proclaiming to be God)
7
The for mystery already is working of lawlessness only the restraining at present until
out of midst
1537 ek (a preposition, written eks before a vowel) – properly, "out from and to"
γίνομαι ἐκ μέσου, to be taken out of the way, to disappear, 2 Thessalonians 2:7; with the genitive of pers, ἐκ μέσου τινων, from the society or company of, out from among:
he might be
8
And then will be revealed the lawless whom the Lord Jesus will slay with the breath of the mouth of Him and will annul by the appearing of the coming of Him, whose is coming
according
2596. kata
Strong's Concordance
kata:
down, against, according to
Original Word: κατά
Part of Speech: Preposition
Transliteration: kata
Phonetic Spelling: (kat-ah')
Definition: down, against, according to
Usage: gen: against, down from, throughout, by; acc: over against, among, daily, day-by-day, each day, according to, by way of.
HELPS Word-studies
2596 katá (a preposition, governing two grammatical cases) –
properly, "down from, i.e. from a higher to a lower plane, with special reference to the terminus (end-point)" (J. Thayer).
[2596 (katá) is written 'kat' or 'kath' before a vowel. So too, kata loses the final a before an initial diphthong (cf. BDF § 17; MH 61-62; R 206-208).
2596 /katá ("bring down exactly, complete") is "opposite" to 303 /aná ("bring up to completion").]
to working of Satan in every power and in signs and in wonders of falsehood
DO YOU REALIZE WHAT YOU ARE SAYING?