Interpreting the 3 ½ years of prophecy
A consistent pattern of interpretation of the 3 ½ years or 1,260 days of Daniel and Revelation, that persists throughout the history of the church, is evident among those scholars who interpreted the period as symbolic, representing the whole age of the church. It is connected to the ministry of Jesus, and completes the prophetic week, in which he confirms his covenant with many. The scholars whose conclusions are presented below understood this.
Methodius of Olympus (died c. 311)
Bishop of Olympus in Lycia, Methodius suffered martyrdom under Maximinus Daia in 311.
On the woman who flees to the wilderness for 1,260 days in Revelation 12:6, Methodius wrote: 
Now she who brings forth, and has brought forth, the masculine Word in the hearts of the faithful, and who passed, undefiled and uninjured by the wrath of the beast, into the wilderness, is, as we have explained, our mother the Church. And the wilderness into which she comes, and is nourished for a thousand two hundred and sixty days, which is truly waste and unfruitful of evils, and barren of corruption, and difficult of access and of transit to the multitude; but fruitful and abounding in pasture, and blooming and easy of access to the holy, and full of wisdom, and productive of life, is this most lovely, and beautifully wooded and well watered abode of Arete [virtue]. … For the Bride of the Word is adorned with the fruits of virtue. And the thousand two hundred and sixty days that we are staying here, O virgins, is the accurate and perfect understanding concerning the Father, and the Son, and the Spirit, in which our mother increases, and rejoices, and exults throughout this time, until the restitution of the new dispensation, when, coming into the assembly in the heavens, she will no longer contemplate the I AM through the means of [human] knowledge, but will clearly behold entering in together with Christ.
Primasius (died c. 560)
He was Augustinian bishop of Hadrumetum and primate of Byzacena, in Africa.
Edward Elliott said Primasius “explained the 42 months, 1260 days, and time times and a half a time, as specially designating the time of Antichrist’s last persecution, yet as signifying also the whole time of the duration of the Church.” 
He was a monk at the Northumbrian monastery of Saint Peter at Monkwearmouth, in Sunderland, England.
On the 1,260 days of Revelation 12:6, he wrote: “In this number of days, which makes three years and a half, he comprehends all the times of Christianity, because Christ, Whose body the Church is, preached the same length of time in the flesh.” 
Alcuin (c. 735-804)
Edward Elliott reported that Alcuin concluded that the period of the ministry of the two witnesses is the whole age of the church. 
Thomas Aquinas (1225-1274)
Thomas was a Sicilian priest of the Catholic Church in the Dominican Order, also known as known as Doctor Angelicus.
Thomas wrote: 
The thousand two hundred sixty days mentioned in the Apocalypse (12:6) denote all the time during which the Church endures, and not any definite number of years. The reason whereof is because the preaching of Christ on which the Church is built lasted three years and a half, which time contains almost an equal number of days as the aforesaid number. Again the number of days appointed by Daniel does not refer to a number of years to elapse before the end of the world or until the preaching of Antichrist, but to the time of Antichrist’s preaching and the duration of his persecution.
John Bale (1495-1563)
Bale was the first to write a commentary on Revelation in English; it was titled The Image of Both Churches.
Bale understood the holy city of Revelation 11:2, which is trampled by gentiles, to be the church, and the 42 months as symbolic. On this verse he said: 
And the holy city (of whom glorious things are spoken) they shall tread under foot for the space of 42 months. Not the earthly Jerusalem is this city, builded of men, and made holy by the outward observations and ceremonies of the Jews as many expositors have fantasied. For of that (as Christ prophesies) is not one stone standing upon another. But this city is the sure building of God, grounded upon the strong foundation of the Apostles and prophets, even upon the hard rock stone Jesus Christ. This is the pleasant possession, the wholesome household, the sure hold, and the delectable vineyard of the Lord of Hosts. This is the living generation of them which feareth, loveth, and seeketh their Lord God in faith, spirit, and truth, and not in outward shadows. These are the children of promise, the true offspring of Abraham, the chosen of Israel, and the kingdom of the holy ghost. Pure, clean, and holy hath Christ made this city, by none other thing but the only shedding of his precious blood.
William Fulke (1538-1589)
Fulke connected the 1,260 days with 70 weeks of years in Daniel 9. He thought the 42 months and 1,260 days represent three and a half years, and signify a limited time, and that “a short space of time is permitted to the devil that he may strive with all his force to beat down the Church.” Fulke wrote on Revelation 11:2-3: 
And the holy city they shall tread under foot two and forty months &c.
The wicked and profane gentiles shall tread under foot, that is, shall grievously oppress, persecute, and afflict the Church of God, to the full space of two and forty months, that is for that time which Christ doth grant unto Antichrist to rage in cruelty against the godly. Some do count the number of months, from the first persecutions of the Christians by the Roman conquerors, even till the time of the emperor Constantine which granted peace, unto the churches. But let them which maintain that opinion see how certain it is. But to me it seems more plain that under numbers the certain fixed, and determinate time of the persecution of Antichrist is assigned, which he cannot pass, although he fret fume and rage never so much. For the Lord hath counted the same time by months days and hours. The reason of the numbers seemeth to be of this sort, this time which sometime is called two and forty months, sometime a thousand two hundred and sixty days, sometime a time two times and half a time, maketh in all three years and an half, that is the one half of a prophetical week, which time also is called three days and an half. And this place alludes to the weeks of years in the 9 Chapter of Daniel. Whereupon we gather to the great consolation of the Church, that a short time is appointed to Antichrist to wait the same, which is also shewed twice afterward in the 12 Chapter and in the 20, that a short space of time is permitted to the devil that he may strive with all his force to beat down the Church, this interpretation as most simple and plain pleases me best; those that seek more subtler may follow their own judgment.
George Gifford (c.1548-1600)
Gifford saw that it was unwise to identify the 1,260 days or the 42 months of Revelation 11:2-3 with specific dates, but instead he argued that in this book, “a number certain is put for an uncertain.” He wrote: 
Then next here is shewed how long the great Antichrist and his rout of profane Gentiles, possessing the outer court of the Temple, shall tread down the holy city. The time is set to be two and forty months: and that is three years and a half: for twelve months to a year, three times twelve is thirty and six, and then six months for the half year, do make up two and forty. From this place the Papists do draw one argument, by which they would prove that the Pope is not Antichrist. After this manner they reason: The Pope hath governed the Church many years: the great Antichrist shall reign but two and forty months, which is three years and a half: (for they do rightly confess that the Gentiles which possess the outer court of the temple, are the rout of Antichrist) therefore say they, it is impossible that the Pope should be Antichrist. For answer unto this: let it be demanded, doth not Saint John in this prophecy speak mystically, even as the Prophets did in old time? they cannot deny this. And then demand further, is not every day put for a year in the seventy weeks which Daniel the Prophet speaketh of? so every week is seven years. And why may not every month here then be put for thirty years? which then do amount unto 1,260 years. Which indeed is a long time in comparison of three years & an half: but compared with the eternity of Christ’s kingdom, it is as nothing. And that is one cause why the Lord numbers it by days & months which quickly run out. But then here will arise another scruple: If the kingdom of Antichrist shall continue twelve hundred and sixty years, we must either say that the Bishop of Rome was Antichrist more than a thousand years past, yea above thirteen hundred, if we take his reign to be no longer than until he was disclosed by the Gospel: or else we must say he hath yet long to continue. Let not this trouble us, seeing it is most clear and out of all controversy, that in this book, a number certain is put for an uncertain. As in the seventh chapter of this book it is said, that of every tribe there was sealed twelve thousand. And because twelve times twelve amount unto one hundred forty & four, it is said chap. 14 that so many thousands stand with the Lamb upon mount Sion. Is any man so unwise, as to take it, that of every tribe there should be saved just twelve thousand neither more nor less, and so on all of the Jews in these latter days just an hundred forty & four thousands to be saved? & not rather that the Lord by a number certain doth declare that even when his Church doth seem utterly to fail, he saves a great number, of which he expresses not the just sum. So in this place when God will comfort his people, he shows that Antichrist shall tread down the holy city but for a short time, that is, two and forty months, which is but three years and an half, he meaneth not to note the just number of years that he shall continue.
Isaac Williams (1802-1865)
Williams was a poet and theologian at Oxford, and was the author of some of the Tracts for the Times associated with the Oxford Movement. In 1845 he became seriously ill, from tuberculosis, or consumption, and was expected to die, but he recovered, and afterwards lived in retirement at Stichcombe in Gloucester. During that period he wrote poetry, and commentaries on scripture. On the 42 months and the 1,260 days of Revelation 11:2-3 and 12:6 and 14, he wrote: 
The “forty-two months” here specified is explained, as by Aretas, Berengaudus, and others, to be the three years and a half of Antichrist; and this will be evident on a little attention to the subject. For the forty-two months, the 1260 days, and the three years and a half, must mean the same period of time, from the manner in which they occur and mutually explain each other; but why they are thus differently expressed is full of mysterious significance. First we have it here stated that the Holy City is trodden under foot for “forty-two months;” and then we find that the continuance of Antichrist is for “forty-two months.” But the whole passage evidently refers to Daniel, where we find it twice expressly stated that the power of Antichrist is for three years and a half, or “a time, times, and the dividing of a time.” And therefore the forty-two months and the three years and a half must mean the same.
It is shown in the like explicit manner that both of these are the same as the 1260 days. It is here stated that the Holy City will be profaned for forty-two months; and it is added in the next verse that the Witnesses will prophesy for 1260 days, meaning this forty-two months of the Church’s desolation.
Ernst Wilhelm Hengstenberg (1802-1869)
A German Lutheran churchman and theologian, Hengstenberg rejected the idea that the 1,260 days refer to a particular time in the history of the world, but instead he interpreted these and related numbers as symbolic, and represented the whole course of the church’s history, and he said the three and a half years were a signature of the church. On Revelation 11:2, he wrote: 
The two and forty months contain only an apparent determination of time; as, indeed, all numbers in the Apocalypse have only an ideal signification; they belong not so properly to the chronological, as to the symbolical forum. The common signature of the dominion of the world over the church in the Revelation, resting on the prophecies of Daniel, (comp. at ch. xii. 6, xiii. 5), is the three and a half, in which we have only to think of the broken seven, the signature of the church. So that the meaning is here conveyed, that however the world may lift itself up, however it may proudly triumph, it can never attain to anything complete and lasting. These three and a half years return again in different forms: a time, two times, and an half time, ch. xii. 14, forty and two months, here and in ch. xiii. 5, 1260 days in ch. xii. 6. In the number of the beast also in ch. xiii. 18, the same thing substantially holds as in these numbers. We have here before us a representation, which does not bring into view some particular period of time in the world’s history, but the whole course of it, only that towards the end every thing realizes itself in a more perfect manner. Wherever the world is found over owing the church, from that of which John himself saw the commencement, to the last in ch. xx. 7-9, of which we have now the beginning before our eyes, there the substance of the prophecy always verifies itself anew, there the obligation still remains to those who are affected by the evil, to take it as the ground of consolation and warning to their hearts. … The thought in this prophecy was in other respects quite correctly apprehended by the older expositors. Thus on the expression, “the holy city shall be trodden down,” Bossuet remarks, “Christians shall be under the sway of the unbelievers; but though the weak shall fall, the church shall continue in strength. This is the first point which St John apprehends in the persecutions: the church continually abiding.”
Christopher Wordsworth (1807-1885)
Wordsworth was an Anglican priest, and canon of Westminster, and he became bishop of Lincoln. He was a gifted scholar. He wrote, on the 1,260 days: 
Now, if we examine the records of Scripture, we find that the period of three years and a half represents an idea; one of spiritual toil, pilgrimage, and persecution.
First, it may be observed, that three and a half, being the half of seven, which is the number of completeness, represents a semi-perfect state; one of transition and probation. … Three years and a half, or forty-two months, or 1260 days, are, as we have seen, the time of the pilgrimage of the Woman in the Wilderness, that is, of the Church in her trials.
In a note, Wordsworth quoted Lightfoot: “The ‘forty-two months,’ ‘1260 days,’ and a ‘time, times, and a half time;’ are but borrowed phrases from Daniel, who so expresses the three and a half years of Antiochus’ persecution (Dan. xii. 7;) and they mean times of trouble, and are used to express that, and not any fixed time… And perhaps it had been much for the reputation of the Commentators upon the Book of Revelation, if they had looked upon that number and the forty and two months, and the thousand two hundred and sixty days as spoken allusively, and not applied it to any precise or determinate time.”
1. Methodius, The Banquet of the ten virgins, or, concerning chastity. In: The writings of Methodius, Alexander of Lycopolis, Peter of Alexandria, and several fragments. Volume 14 of Ante-Nicene Christian library. T. & T. Clark, 1869. p. 75.
2. Elliott, Edward Bishop. Horae apocalypticae: or a commentary on the Apocalypse. Volume 3. p. 235.
3. Bede (the venerable.) The explanation of the Apocalypse. Translated by Edward Marshall, 1878. p. 83.
4. Elliott, Edward Bishop. Ibid., p. 126.
5. Aquinas, Thomas. Summa Theologica. Treatise on the resurrection. Question 77.2.2.
6. John Bale, The Image of Both Churches. 1547. (Spelling is modified in the quote.)
7. Fulke, William. Praelections vpon the sacred and holy Reuelation of S. Iohn, written in latine by William Fulke Doctor of Diuinitie, and translated into English by George Gyffard. 1573.
8. Gifford, George. Sermons vpon the whole booke of the Reuelation Set forth by George Giffard, Preacher of the Word at Mauldin in Essex. Richard Field and Felix Kinston, 1599. p. 189-190.
9. Williams, Isaac. The Apocalypse, with notes and reflections. Rivington, 1852. pp. 185-187.
10. Hengstenberg, Ernst Wilhelm. The Revelation of St John: expounded for those who search the Scriptures, Volume 1. T. & T. Clark, 1851. p. 396
11. Wordsworth, Christopher. Lectures on the Apocalypse: critical, expository, and practical, delivered before the University of Cambridge. (Hulsean lectures) 2nd. ed. H. Hooker, 1852. pp. 205-209.