Quotations about:
    epoch

Ours is the crowning era foretold in prophecy;
Born of Time, a great new cycle of centuries
Begins. Justice returns to earth, the Golden Age
Returns, and its first-born comes down from heaven above.
Look kindly, chaste Lucina, upon this infant’s birth,
For with him shall hearts of iron cease, and hearts of gold
Inherit the whole earth — yes, Apollo reigns now.
 
[Ultima Cumaei venit iam carminis aetas;
magnus ab integro saeclorum nascitur ordo:
iam redit et Virgo, redeunt Saturnia regna;
iam nova progenies caelo demittitur alto.
Tu modo nascenti puero, quo ferrea primum
desinet ac toto surget gens aurea mundo,
casta fave Lucina: tuus iam regnat Apollo.]

Virgil (70-19 BC) Roman poet [b. Publius Vergilius Maro; also Vergil]

Eclogues [Eclogae, Bucolics, Pastorals], No. 4 “Pollio,” l. 5ff (4.5-11) (42-38 BC) [tr. Day Lewis (1963)]
    (Source)

Celebrating the birth of Saloninus, a boy born in the consulship of his father and Virgil's patron C. Asinius Pollio. Or, possibly, writing of Marcellus, son of Augustus. Or maybe just a lot of veiled references to Augustus himself. Or, say some, divine prophecy of the future Jesus Christ. Lots of theories; some summaries here and here.

References in the various translations are to (a) the prophetic Sybil of Cumae (near Naples); (b) the virgin goddess of Justice, Astraea, who left the world after the first Golden Age to become the constellation Virgo; (c) the goddess of birth, Lucina, who is also identified with Diana, the sister of Apollo.

(Source (Latin)). Alternate translations:

And times great order now again is borne,
The maid returns, Saturnian Realms returne:
Now from high Heaven springs a new Progenie.
To th' infant chaste Lucina favouring be,
Who ending iron ages, through all Lands
Shall golden plant: thy Phoebus now commands.
[tr. Ogilby (1649)]

The last great Age, foretold by sacred Rhymes,
Renews its finish'd Course, Saturnian times
Roll round again, and mighty years, begun
From their first Orb, in radiant Circles run.
The base degenerate Iron offspring ends;
A golden Progeny from Heav'n descends.
O chaste Lucina speed the Mother's pains,
And haste the glorious Birth; thy own Apollo reigns!
[tr. Dryden (1709)]

Comes the last age, by Cumæ's maid foretold:
'Afresh the mighty line of years unroll'd,
The Virgin now, now Saturn's sway returns;
Now the blest globe a heaven-sprung Child adorns,
Whose genial power shall whelm earth's iron race,
And plant once more the golden in its place.
Thou, chaste Lucina, but that child sustain:
And, lo! disclosed thine own Apollo's reign!
[tr. Wrangham (1830)]

The last era, of Cumæan song, is now arrived: The great series of ages begins anew. Now, too, returns the virgin Astræa, returns the reign of Saturn; now a new progeny is sent down from high heaven. Be thou but propitious to the infant boy, under whom first the iron age shall cease, and the golden age overall the world arise, O chaste Lucina; now thy own Apollo reigns.
[tr. Davidson (1854)]

Come are those last days that the Sybil sang:
The ages' mighty march begins anew.
Now comes the virgin, Saturn reigns again:
Now from high heaven descends a wondrous race.
Thou on the newborn babe -- who first shall end
That age of iron, bid a golden dawn
Upon the broad world -- Lucina, smile:
Now thy Apollo reigns.
[tr. Calverley (c. 1871)]

The last æra of Sibylline prophecy has come at last; a mighty cycle of ages is being born afresh. At length the maiden Astraea is returning; the happy reign of Saturn is returning; now a new and better race is descending from the realms on high. Do thou only, chaste Lucina, smile on the birth of the boy, under whose auspices the iron brood shall first begin to fail, and a golden race shall rise throughout the world: thine own Apollo is now on his throne.
[tr. Wilkins (1873)]

See the last era of prophetic voice!
The world and its inhabitants rejoice.
With a fair offspring of celestial birth,
The reign of innocence returns to earth.
Apollo, fulgent god of beauteous dawn,
And chaste Diana, bless the glorious morn.
The iron age retires; the boy is born.
[tr. King (1882), l. 267ff]

At last they dawn; those latter days, so long
Prefigured in the old Cumæan song:
Fresh as the dew of earth's primeval morn,
Of this great series the first age is born:
The lost Astraea greeting us again,
The olive, and the just Saturnian reign:
Already the first fruit is largely given,
And a new progeny descends from heaven,
The links of iron ages to destroy,
(Thou, virgin ever helpful, speed the boy)
And with a golden race to fill the way
From Nile to Thule: give him to the day,
Purest Lucina: circling time explains
The Sibyl, and thy own Apollo reigns.
[tr. Palmer (1883)]

Now the last age by Cumæ's Sibyl sung
has come and gone, and the majestic roll
of circling centuries begins anew:
justice returns, returns old Saturn's reign,
with a new breed of men sent down from heaven.
Only do thou, at the boy's birth in whom
the iron shall cease, the golden race arise,
befriend him, chaste Lucina; 'tis thine own
Apollo reigns.
[tr. Greenough (1895)]

The last era of Cumæan song, has now arrived: The great series of ages begins anew. Now, too, returns the virgin Astræa, the reign of Saturn returns; now a new race of men is being sent down from high heaven. And in a special degree, O chaste Lucina, be but propitious to the infant boy, under whom first the iron age shall cease, and the golden age arise over all the world; now your own brother Apollo reigns.
[tr. Bryce (1897)]

Now is come the last age of the Cumæan prophecy: the great cycle of periods is born anew. Now returns the Maid, returns the reign of Saturn: now from high heaven a new generation comes down. Yet do thou at that boy's birth, in whom the iron race shall begin to cease, and the golden to arise over all the world, holy Lucina, be gracious; now thine own Apollo reigns.
[tr. Mackail (1899)]

Now dawns the last age of Cumæan song!
Once more the circling centuries begin --
The Virgin reappears and Saturn reigns:
From heav'n descends a novel progeny;
Now to this child in whom the iron race
Throughout the world shall cease and turn to gold,
Extend thy aid, Lucina, chaste and kind,
For thy Apollo reigns.
[tr. Mackail/Cardew (1908)]

Now come the world's last days, the age foretold
By Cumae's prophetess in sacred song.
The vast world-process brings a new-born time.
Once more the Virgin comes and Saturn's reign.
Behold a heaven-born offspring earthward hies! Holy Lucina, lend thy light and aid
The while this child is born before whose power
The iron race of mortals shall away,
And o'er this earth a golden people reign.
For blest Apollo is at last their king.
[tr. Williams (1915)]

Now is come the last age of Cumaean song; the great line of the centuries begins anew. Now the Virgin returns, the reign of Saturn returns; now a new generation descends from heaven on high. Only do you, pure Lucina, smile on the birth of the child, under whom the iron brood shall at last cease and a golden race spring up throughout the world! Your own Apollo now is king!
[tr. Fairclough (Loeb) (1916)]

The last age told by Cumae's seer is come,
A might roll of generations new
Is now arising. Justice now returns
And Saturn's realm, and from high heaven descends
A worthier race of men. Only do thou
Smile, chaste Lucina, on the infant boy,
With whom the iron age will pass away,
The golden age in all the earth be born;
For thine Apollo reigns.
[tr. Royds (1922)]

We have reached the last era in Sibylline song. Time has conceived and the great Sequence of the Ages starts afresh. Justice, the Virgin, comes back to dwell with us, and the rule of Saturn is restored. The Firstborn of the New Age is already on his way from high heaven down to earth. With him, the Iron Race shall end and Golden Man inherit all the world. Smile on the Baby's birth, immaculate Lucina; your own Apollo is enthroned.
[tr. Rieu (1949)]

At last approaches that era the Sibyl foreshadowed,
The centuries flower afresh in a great world-order,
Justice, the Virgin, returns, and the peace of Saturn;
Already the new race ventures from heights of heaven.
All that we ask, immaculate Mother of childbirth,
Is your smile on the baby born, who finally cancels
The breed of iron and fosters the golden-hearted
Throughout the world: your own Light-giver has triumphed!
[tr. Johnson (1960)]

The last great age the Sybil told has come;
The new order of centuries is born;
The Virgin now returns; and the reign of Saturn;
The new generation now comes down from heaven.
Lucina, look with favor on this child,
-- Lucina, goddess, pure -- this child by whom
The Age of Iron gives way to the Golden Age.
Now is the time of your Apollo's reign.
[tr. Ferry (1999)]

Now the last age of the Cumaean prophecy begins:
the great roll-call of the centuries is born anew:
now Virgin Justice returns, and Saturn’s reign:
now a new race descends from the heavens above.
Only favour the child who’s born, pure Lucina, under whom
the first race of iron shall end, and a golden race
rise up throughout the world: now your Apollo reigns.
[tr. Kline (2001)]