Well, the idea is not wholly unanticipated in the canon; there is always the Prayer of Moses; the paracanonical Jubilees also expresses the thought:Bernard Muller wrote: ↑Sat Oct 28, 2017 1:47 pmIn 2 Peter 3:8 (and only here in the canonical texts) a day is equal to one thousand years:3. The teaching about the Second Coming in the writings attributed to Justin is paralleled in the Revelation of John---Not the Pauline Epistles---Justin did not teach that people would meet Jesus in the air. Justin claimed people would with Jesus in Jerusalem for a thousand years on earth.
"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"
Psalm 90.4 (89.4 LXX): For a thousand years in Your sight are like the day, yesterday, when it passes by, or as a watch in the night. / ὅτι χίλια ἔτη ἐν ὀφθαλμοῖς σου ὡς ἡ ἡμέρα ἡ ἐχθές ἥτις διῆλθεν καὶ φυλακὴ ἐν νυκτί.
Jubilees 4.29-30: 29 And at the close of the nineteenth jubilee, in the seventh week in the sixth year thereof, Adam died, and all his sons buried him in the land of his creation, and he was the first to be buried in the earth. 30 And he lacked seventy years of one thousand years; for one thousand years are as one day in the testimony of the heavens and therefore was it written concerning the tree of knowledge: 'On the day that ye eat thereof ye shall die.' For this reason he did not complete the years of this day; for he died during it.
Jubilees 4.29-30: 29 And at the close of the nineteenth jubilee, in the seventh week in the sixth year thereof, Adam died, and all his sons buried him in the land of his creation, and he was the first to be buried in the earth. 30 And he lacked seventy years of one thousand years; for one thousand years are as one day in the testimony of the heavens and therefore was it written concerning the tree of knowledge: 'On the day that ye eat thereof ye shall die.' For this reason he did not complete the years of this day; for he died during it.
ETA: The idea got around:
Barnabas 15.1-5: 1 And, moreover, concerning the sabbath it is written in the ten commandments, in which he spake on Mount Sinai unto Moses face to face: Sanctify ye the sabbath of the Lord with pure hands and a pure heart. 2 And in another place he saith, If my sons shall keep my sabbath, then will I place my mercy upon them. 3 He speaketh, too, of the sabbath in the beginning of the creation: And God made in six days the works of his hands, and finished them on the seventh day, and rested in it and sanctified it. 4 Consider, my children, what signify the words, He finished them in six days. They mean this: that in six thousand years the Lord will make an end of all things, for a day is with him as a thousand years. And he himself beareth witness unto me, saying: Behold this day a day shall be as a thousand years. Therefore, my children, in six days, that is in six thousand years, shall all things be brought to an end. 5 And the words, He rested on the seventh day, signify this: After that his Son hath come, and hath caused to cease the time of the wicked one, and hath judged the ungodly, and changed the sun and the moon and the stars, then shall he rest well on the seventh day.
Irenaeus, Against Heresies 5.28.3: For in as many days as this world was made, in so many thousand years shall it be concluded. And for this reason the Scripture says: "Thus the heaven and the earth were finished, and all their adornment. And God brought to a conclusion upon the sixth day the works that He had made; and God rested upon the seventh day from all His works." This is an account of the things formerly created, as also it is a prophecy of what is to come. For the day of the Lord is as a thousand years; and in six days created things were completed: it is evident, therefore, that they will come to an end at the sixth thousand year.
Irenaeus, Against Heresies 5.28.3: For in as many days as this world was made, in so many thousand years shall it be concluded. And for this reason the Scripture says: "Thus the heaven and the earth were finished, and all their adornment. And God brought to a conclusion upon the sixth day the works that He had made; and God rested upon the seventh day from all His works." This is an account of the things formerly created, as also it is a prophecy of what is to come. For the day of the Lord is as a thousand years; and in six days created things were completed: it is evident, therefore, that they will come to an end at the sixth thousand year.
