Oh sure, it's a different day of the Lord
Your theory of there being only one day of the Lord is ridiculous.
Eze 13:5 Ye have not gone up into the gaps, neither made up the hedge for the house of Israel to stand in the battle in the day of the LORD.
Eze 13:6 They have seen vanity and lying divination, saying, The LORD saith: and the LORD hath not sent them: and they have made others to hope that they would confirm the word.
Here is a completely different "day of the Lord" not associated with the second coming or the day the Lord casts sinners in the LOF.
There are MANY days of the Lord. A day of the Lord is a day when God does something important. There are many of them.
2Pe 3:7 But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men.
2Pe 3:8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day.
2Pe 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
2Pe 3:10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.
The context here is clearly not the second coming but the day of the GWTJ. This is the day Peter was describing:
Rev 20:11 And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them.
Rev 20:12 And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.
Rev 20:13 And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works.
Rev 20:14 And death and hell were cast into the lake of fire. This is the second death.
Rev 20:15 And whosoever was not found written in the book of life was cast into the lake of fire.
Rev 21:1
And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
Rev 21:2 And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.