I think what we are suggesting is even clearer in Book 5 of Adv Haer. In other words, Apollinaris merely took over Irenaeus's interpretation of Daniel 9:24 - 27 whereby 7 weeks = the birth and crucifixion of Jesus followed by 62 weeks of 'the building of the temple' i.e. the Christian religion followed by the rise of the Antichrist c. 482 CE followed in turn by the manifestation of the kingdom of God on earth. Let's look at an important passage in Irenaeus. Irenaeus says that Jesus establishes all the kings of the world. In Adv Haer 5.24.1 we read:
As therefore the devil lied at the beginning, so did he also in the end, when he said, "All these are delivered unto me, and to whomsoever I will I give them." For it is not he who has appointed the kingdoms of this world, but God; for "the heart of the king is in the hand of God." And the Word also says by Solomon, "By me kings do reign, and princes administer justice. By me chiefs are raised up, and by me kings rule the earth." Paul the apostle also says upon this same subject: "Be ye subject to all the higher powers; for there is no power but of God: now those which are have been ordained of God."
In other words, Caesar himself is the legitimate ruler of the world according to Irenaeus, established by god as cosmocrator. This helps us understand not only why the Roman Church escaped persecution in the age but more importantly how Irenaeus could understand Daniel 9:24 - 27 to apply to the Church as the 'restored temple.'
To this end, given that Irenaeus accepts the legitimacy of Commodus and Septimius Severus he distinguishes the coming of one who is not appointed by God - i.e. the Antichrist:
And not only by the particulars already mentioned, but also by means of the events which shall occur in the time of Antichrist is it shown that he, being an apostate and a robber, is anxious to be adored as God; and that, although a mere slave, he wishes himself to be proclaimed as a king. For he (Antichrist) being endued with all the power of the devil, shall come, not as a righteous king, nor as a legitimate king, in subjection to God, but an impious, unjust, and lawless one; as an apostate, iniquitous and murderous; as a robber, concentrating in himself [all] satanic apostasy, and setting aside idols to persuade [men] that he himself is God, raising up himself as the only idol, having in himself the multifarious errors of the other idols. This he does, in order that they who do [now] worship the devil by means of many abominations, may serve himself by this one idol, of whom the apostle thus speaks in the second Epistle to the Thessalonians: "Unless there shall come a failing away first, and the man of sin shall be revealed, the son of perdition, who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he sitteth in the temple of God, showing himself as if he were God." The apostle therefore clearly points out his apostasy, and that he is lifted up above all that is called God, or that is worshipped--that is, above every idol--for these are indeed so called by men, but are not [really] gods; and that he will endeavour in a tyrannical manner to set himself forth as God.
Moreover, he (the apostle) has also pointed out this which I have shown in many ways, that the temple in Jerusalem was made by the direction of the true God. For the apostle himself, speaking in his own person, distinctly called it the temple of God. Now I have shown in the third book, that no one is termed God by the apostles when speaking for themselves, except Him who truly is God, the Father of our Lord, by whose directions the temple which is at Jerusalem was constructed for those purposes which I have already mentioned; in which [temple] the enemy shall sit, endeavouring to show himself as Christ, as the Lord also declares: "But when ye shall see the abomination of desolation, which has been spoken of by Daniel the prophet, standing in the holy place (let him that readeth understand), then let those who are in Judea flee into the mountains; and he who is upon the house-top, let him not come down to take anything out of his house: for there shall then be great hardship, such as has not been from the beginning of the world until now, nor ever shall be."
Daniel too, looking forward to the end of the last kingdom, i.e., the ten last kings, amongst whom the kingdom of those men shall be partitioned, and upon whom the son of perdition shall come, declares that ten horns shall spring from the beast, and that another little horn shall arise in the midst of them, and that three of the former shall be rooted up before his face. He says: "And, behold, eyes were in this horn as the eyes of a man, and a mouth speaking great things, and his look was more stout than his fellows. I was looking, and this horn made war against the saints, and prevailed against them, until the Ancient of days came and gave judgment to the saints of the most high God, and the time came, and the saints obtained the kingdom." Then, further on, in the interpretation of the vision, there was said to him: "The fourth beast shall be the fourth kingdom upon earth, which shall excel all other kingdoms, and devour the whole earth, and tread it down, and cut it in pieces. And its ten horns are ten kings which shall arise; and after them shall arise another, who shall surpass in evil deeds all that were before him, and shall overthrow three kings; and he shall speak words against the most high God, and wear out the saints of the most high God, and shall purpose to change times and laws; and [everything] shall be given into his hand until a time of times and a half time," that is, for three years and six months, during which time, when he comes, he shall reign over the earth. Of whom also the Apostle Paul again, speaking in the second [Epistle] to the Thessalonians, and at the same time proclaiming the cause of his advent, thus says: "And then shall the wicked one be revealed, whom the Lord Jesus shall slay with the spirit of His mouth, and destroy by the presence of His coming; whose coming [i.e., the wicked one's] is after the working of Satan, in all power, and signs, and portents of lies, and with all deceivableness of wickedness for those who perish; because they did not receive the love of the truth, that they might be saved. And therefore God will send them the working of error, that they may believe a lie; that they all may be judged who did not believe the truth, but gave consent to iniquity,"
Clearly then Daniel 9:27 is yet to be fulfilled for Irenaeus - making it obvious that his system is likely the same as Apollinaris's. In other words, the seven weeks are fulfilled but the Church is living in the midst of the 62 weeks and the final week is yet to come when the Antichrist arises just as with Apollinaris's system.
Irenaeus goes on to cite material from Daniel and other sources to demonstrate to his readers that the final week where the Antichrist appears is yet to come. We read in what immediately follows our last citation:
The Lord also spoke as follows to those who did not believe in Him: "I have come in my Father's name, and ye have not received Me: when another shall come in his own name, him ye will receive," calling Antichrist "the other," because he is alienated from the Lord. This is also the unjust judge, whom the Lord mentioned as one "who feared not God, neither regarded man," to whom the widow fled in her forgetfulness of God,--that is, the earthly Jerusalem,--to be avenged of her adversary. Which also he shall do in the time of his kingdom: he shall remove his kingdom into that [city], and shall sit in the temple of God, leading astray those who worship him, as if he were Christ. To this purpose Daniel says again: "And he shall desolate the holy place; and sin has been given for a sacrifice, and righteousness been cast away in the earth, and he has been active (fecit), and gone on prosperously." And the angel Gabriel, when explaining his vision, states with regard to this person: "And towards the end of their kingdom a king of a most fierce countenance shall arise, one understanding [dark] questions, and exceedingly powerful, full of wonders; and he shall corrupt, direct, influence (faciet), and put strong men down, the holy people likewise; and his yoke shall be directed as a wreath [round their neck]; deceit shall be in his hand, and he shall be lifted up in his heart: he shall also ruin many by deceit, and lead many to perdition, bruising them in his hand like eggs." And then he points out the time that his tyranny shall last, during which the saints shall be put to flight, they who offer a pure sacrifice unto God: "And in the midst of the week," he says, "the sacrifice and the libation shall be taken away, and the abomination of desolation [shall be brought] into the temple: even unto the consummation of the time shall the desolation be complete." Now three years and six months constitute the half-week.
From all these passages are revealed to us, not merely the particulars of the apostasy, and [the doings] of him who concentrates in himself every satanic error, but also, that there is one and the same God the Father, who was declared by the prophets, but made manifest by Christ. For if what Daniel prophesied concerning the end has been confirmed by the Lord, when He said, "When ye shall see the abomination of desolation, which has been spoken of by Daniel the prophet" (and the angel Gabriel gave the interpretation of the visions to Daniel, and he is the archangel of the Creator (Demiurgi), who also proclaimed to Mary the visible coining and the incarnation of Christ), then one and the same God is most manifestly pointed out, who sent the prophets, and made promise of the Son, and called us into His knowledge.
In a still clearer light has John, in the Apocalypse, indicated to the Lord's disciples what shall happen in the last times, and concerning the ten kings who shall then arise, among whom the empire which now rules [the earth] shall be partitioned. He teaches us what the ten horns shall be which were seen by Daniel, telling us that thus it had been said to him: "And the ten horns which thou sawest are ten kings, who have received no kingdom as yet, but shall receive power as if kings one hour with the beast. These have one mind, and give their strength and power to the beast. These shall make war with the Lamb, and the Lamb shall overcome them, because He is the Lord of lords and the King of kings." It is manifest, therefore, that of these [potentates], he who is to come shall slay three, and subject the remainder to his power, and that he shall be himself the eighth among them. And they shall lay Babylon waste, and burn her with fire, and shall give their kingdom to the beast, and put the Church to flight. After that they shall be destroyed by the coming of our Lord. For that the kingdom must be divided, and thus come to ruin, the Lord [declares when He] says: "Every kingdom divided against itself is brought to desolation, and every city or house divided against itself shall not stand." It must be, therefore, that the kingdom, the city, and the house be divided into ten; and for this reason He has already foreshadowed the partition and division [which shall take place]. Daniel also says particularly, that the end of the fourth kingdom consists in the toes of the image seen by Nebuchadnezzar, upon which came the stone cut out without hands; and as he does himself say: "The feet were indeed the one part iron, the other part clay, until the stone was cut out without hands, and struck the image upon the iron and clay feet, and dashed them into pieces, even to the end." Then afterwards, when interpreting this, he says: "And as thou sawest the feet and the toes, partly indeed of clay, and partly of iron, the kingdom shall be divided, and there shall be in it a root of iron, as thou sawest iron mixed with baked clay. And the toes were indeed the one part iron, but the other part clay." The ten toes, therefore, are these ten kings, among whom the kingdom shall be partitioned, of whom some indeed shall be strong and active, or energetic; others, again, shall be sluggish and useless, and shall not agree; as also Daniel says: "Some part of the kingdom shall be strong, and part shall be broken from it. As thou sawest the iron mixed with the baked clay, there shall be minglings among the human race, but no cohesion one with the other, just as iron cannot be welded on to pottery ware." And since an end shall take place, he says: "And in the days of these kings shall the God of heaven raise up a kingdom which shall never decay, and His kingdom shall not be left to another people. It shall break in pieces and shatter all kingdoms, and shall itself be exalted for ever. As thou sawest that the stone was cut without hands from the mountain, and brake in pieces the baked clay, the iron, the brass, the silver, and the gold, God has pointed out to the king what shall come to pass after these things; and the dream is true, and the interpretation trustworthy."
If therefore the great God showed future things by Daniel, and confirmed them by His Son; and if Christ is the stone which is cut out without hands, who shall destroy temporal kingdoms, and introduce an eternal one, which is the resurrection of the just; as he declares, "The God of heaven shall raise up a kingdom which shall never be destroyed,"--let those thus confuted come to their senses, who reject the Creator (Demiurgum), and do not agree that the prophets were sent beforehand from the same Father from whom also the Lord came, but who assert that prophecies originated from diverse powers. For those things which have been predicted by the Creator alike through all the prophets has Christ fulfilled in the end, ministering to His Father's will, and completing His dispensations with regard to the human race. Let those persons, therefore, who blaspheme the Creator, either by openly expressed words, such as the disciples of Marcion, or by a perversion of the sense [of Scripture], as those of Valentinus and all the Gnostics falsely so called, be recognised as agents of Satan by all those who worship God; through whose agency Satan now, and not before, has been seen to speak against God, even Him who has prepared eternal fire for every kind of apostasy. For he did not venture to blaspheme his Lord openly of himself; as also in the beginning he led man astray through the instrumentality of the serpent, concealing himself as it were from God. Truly has Justin remarked: That before the Lord's appearance Satan never dared to blaspheme God, inasmuch as he did not yet know his own sentence, because it was contained in parables and allegories; but that after the Lord's appearance, when he had clearly ascertained from the words of Christ and His apostles that eternal fire has been prepared for him as he apostatized from God of his own free-will, and likewise for all who unrepentant continue in the apostasy, he now blasphemes, by means of such men, the Lord who brings judgment [upon him] as being already condemned, and imputes the guilt of his apostasy to his Maker, not to his own voluntary disposition. Just as it is with those who break the laws, when punishment overtakes them: they throw the blame upon those who frame the laws, but not upon themselves. In like manner do those men, filled with a satanic spirit, bring innumerable accusations against our Creator, who has both given to us the spirit of life, and established a law adapted for all; and they will not admit that the judgment of God is just. Wherefore also they set about imagining some other Father who neither cares about nor exercises a providence over our affairs, nay, one who even approves of all sins.
In other words, Marcion and Valentinus and the rest of the heretics are wicked because - living in the 62 week period where the temple has been restored, they insist on promoting a doctrine which divorces Jesus from the cosmocrator, the ruler of the world. I can't help but think there is a political dimension emerging here - Marcion and Valentinus were guilty of not acknowledging that Caesar was the divinely appointed cosmocrator by Jesus. Otherwise how could Irenaeus claim that the Christian Church was living in the age of the 62 weeks? Clearly Irenaeus connects Daniel's list of kingdoms 'divinely appointed' as they are with the 490 week prediction.
In other words, if Israel could view Cyrus as the messiah for his facilitating the restoration of the true religion surely Irenaeus saw it fit to do the same with respect to Caesar.