This might be the impression we get from a certain pasuk in parshat Noach. After the flood, after Hashem smells the sweet savor of the sacrifice, Hashem says:
|כב עֹד, כָּל-יְמֵי הָאָרֶץ: זֶרַע וְקָצִיר וְקֹר וָחֹם וְקַיִץ וָחֹרֶף, וְיוֹם וָלַיְלָה--לֹא יִשְׁבֹּתוּ.||22 While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.'|
It does not say forever, but rather so long as the earth remains. Now, we could say that the very theme here is to connect the weather conditions and natural order to something related which is constant and everlasting. But on the other hand, one can read this as that for the rest of Earth's allotted timespan, these shall not cease.
Thus, Ibn Ezra writes:
ח, כבעוד כל ימי הארץ וגו. -לאות כי יש לה קץ קצוב.ומה נכבד דרש סביב שמנה עשרה אלף. רק לא ידענו אחד מני אלף:
Thus, there is a ketz, and someone darshens it as being 18,000 years, based on a pasuk at the end of Yechezkel (see the commentary of Ohel Yosef here). But no one knows the time of the ketz of the end of the world.
Ibn Caspi argues on Ibn Ezra, asserting that this does not compel us to maintain that the world will end. And he says that this is the position of Rambam in Moreh Nevuchim, volume II, chapter 28, because Rambam admits partially to Aristotle. While arguing that the Earth did have a fixed point of creation, such that it has not as of yet existed for an infinite number of years, it will exist forever with no fixed end. (See here, and see Ibn Kaspi's supercommentary on it in Amudei Kesef.)
This is perhaps a good place to discuss the concept of ketz for the end of the world, in general. This might not be the same as a ketz for mashiach, and perhaps the injunctions against the latter do not apply to the former. Or perhaps not. Because there seems to be ideas of techiyas hameisim after the end of the world, but on the other hand many of the preceding years are years of mashiach.
There is one famous one in Bavli, in Sanhedrin daf 97:
R. Kattina said: Six thousand years shall the world exist, and one [thousand, the seventh], it shall be desolate, as it is written, And the Lord alone shall be exalted in that day.32 Abaye said: it will be desolate two [thousand], as it is said, After two days will he revive us: in the third day, he will raise us up, and we shall live in his sight.33It has been taught in accordance with R. Kattina: Just as the seventh year is one year of release in seven, so is the world: one thousand years out of seven shall be fallow, as it is written, And the Lord alone shall be exalted in that day,' and it is further said, A Psalm and song for the Sabbath day,34 meaning the day that is altogether Sabbath — 35 and it is also said, For a thousand years in thy sight are but as yesterday when it is past.36The Tanna debe Eliyyahu teaches: The world is to exist six thousand years. In the first two thousand there was desolation;37 two thousand years the Torah flourished;38 and the next two thousand years is the Messianic era,39 but through our many iniquities all these years have been lost.1Elijah said to Rab Judah, the brother of R. Salia the pious: 'The world shall exist not less than eighty five jubilees,2 and in the last jubilee the son of David will come.'3 He asked him, 'At the beginning or at the end?'4 — He replied, 'I do not know.' 'Shall [this period] be completed or not?'5 — 'I do not know,' he answered. R. Ashi said: He spoke thus to him, 'Before that, do not expect him; afterwards thou mayest await him.'6R. Hanan b. Tahlifa sent [word] to R. Joseph: I once met a man who possessed a scroll written in Hebrew in Assyrian characters.7 I said to him: 'Whence has this come to thee?' He replied, 'I hired myself as a mercenary in the Roman army, and found it amongst the Roman archives. In it is stated that four thousand, two hundred and thirty8-one years after the creation the world will be orphaned.9 [As to the years following,] some of them will be spent in the war of the great sea monsters,10 and some in the war of Gog and Magog, and the remaining [period] will be the Messianic era, whilst the Holy One, blessed be He, will renew his world only after seven thousand years.' R. Abba the son of Raba said: The statement was after five thousand years.
While there is reference to a messianic era preceding the end, there is also a reference to the end. And this end would come at the termination of 7000 years (though the last thousand was desolation), or the termination of 8000 years (though the last two thousand were desolation), or perhaps 4250 years (=85 Jubilees) or 4300 years (the preceding plus one yovel), or perhaps 5000 years (in R' Abba bar Rava's statement).
We are now in 5770, or if it is the case that we are missing 185 years, we are in 5935. Which makes the year 6000 just around the corner. What if mashiach doesn't come by then? Would the shock be too much to handle, causing Jews to abandon Judaism en mass?
I doubt it, because someone will find an answer, just as they found an answer back when everyone was certain that the ketz was 1212 CE, and it did not arrive. In fact, I can provide an answer already today. There is a dispute whether 2000 years or 1000 years the world was to be fallow. If 2000 years, then they already encountered it (since it was from 4001 - 6000 CE), but the answer was just that mashiach could have come then, but through our iniquities, those years were lost to us, and mashiach did not yet arise. If the year 6000 comes and goes, we can similarly work with 1000 years fallow, but losing even years of that due to our iniquities.
But what if the year 7000 arrives without mashiach, and without the end of the world?! We could say we are living in the period of desolation, I suppose, but that desolation should be desolation. There does not seem to be wiggle room. Unless we can live in desolation unitl the termination of the 8000th year. And then certainly the world should be over. But what if not?
But keep in mind R' Abba bar Abaye said 5000 years. I think this is somewhat relevant to a Yerushalmi I'd like to discuss. In Yerushalmi Shabbat 39b, towards the very end of perek six, we read:
The black text is the words of the Yerushalmi while the blue text is from Yedid Nefesh's commentary, drawn from Pnei Moshe. The idea presented is that when Bilaam prophesied, he spoke at the precise midpoint of the world's existence, and this was the year 2486 to the Creation of the World. And in the same amount of time, the prophecy would turn and the redemption would come. 2486 X 2 = 4972. This works out to 1212 CE. Yet Mashiach didn'tcome! What gives? Did Rabbi Chanina son of Rabbi Abahu predict the Ketz, but incorrectly?
I would nitpick slightly with this interpretation. In parshat Bo, in Shemot 11:4, we read about Makat Bechorot:
|ד וַיֹּאמֶר מֹשֶׁה, כֹּה אָמַר ה': כַּחֲצֹת הַלַּיְלָה, אֲנִי יוֹצֵא בְּתוֹךְ מִצְרָיִם.||4 And Moses said: 'Thus saith the LORD: About midnight will I go out into the midst of Egypt;|
and Rashi says on this:
|At the dividing point of the night: Heb. כַּחִצֹתהַלַיְלָה, when the night is divided. כַּחִצֹת is like “when the meal offering was offered up (כַּעִלוֹת) ” (II Kings 3:20); [and like] “when their anger was kindled (בַּחִרוֹת) against us” (Ps. 124:3). This is its simple meaning, which fits its context that חִצֹת is not a noun denoting a half. Our Rabbis, however, interpreted it like כַּחִצִי הַלַיְלָה, at about midnight [lit., half the night], and they said that Moses said כַּחִצֹת, about midnight, meaning near it [midnight], either before it or after it, but he did not say בַּחִצֹת, at midnight, lest Pharaoh’s astrologers err and [then] say, “Moses is a liar,” but the Holy One, blessed be He, Who knows His times and His seconds, בַּחִצוֹת, at midnight. — [from Ber. 3b]||כחצת הלילה: כהחלק הלילה, כחצות, כמו (מלכים א' יט כה) כעלות, (תהלים קכד ג) בחרות אפם בנו, זהו פשוטו לישבו על אופניו, שאין חצות שם דבר של חצי. ורבותינו דרשוהו כמו בחצי הלילה (שמות יב כט) ואמרו, שאמר משה כחצות, דמשמע סמוך לו או לפניו או לאחריו, ולא אמר בחצות, שמא יטעו אצטגניני פרעה, ויאמרו משה בדאי הוא:|
Why do I mention this? How does this relate? Because I think Pnei Moshe is being way too exacting when he notes that it is 2486 years when Bilaam spoke. 2486 is only 14 years away from the year 2500.
I would note that different cultures have different beliefs about the length of the world. Indeed, Zoroastrians believe in world cycles of 3000, for a total of 12,000 years.
As we saw above, R' Abba bar Rava spoke of a 5000 year cycle, and I would claim that this matches the Yerushalmi. The Yerushalmi said that Bilaam was standing in the middle of the world's time. Not until mashiach, but until the end. If so, when mashiach did not arrive in 1212 CE, they answered that it was an opportune time that was missed. That could work if it were a possible ketz for mashiach, but that was not the claim. It was a claim as to the end of the entire world, or else Bilaam would not have been standing in the middle of it!
I would claim what was intended was the end of the world, and that set time was a bit later than understood -- that is, the year 5000 rather than the year 4972.
And if it came and went, then this is simply evidence that the assumption by the Yerushalmi as to the span of the Earth's existence was incorrect. Which is not surprising, especially as there are multiple competing predictions.
I would also note that Rambam in his Iggeret Teiman gives 1212 CE as a ketz for mashiach he received via tradition. So he understands it as a ketz for mashiach. On the other hand, it is possible that he could not understand it any other way. After all, he wrote in Moreh Nevuchim that there is no end to the earth, but that it continues on infinitely.
For those of us who maintain that evolution indeed occurred, and that the age of the earth is 4.5 billions years old, we have a stronger question to grapple with. 7000 years passed many billions of years ago! A 6000 year timespan makes sense when working with a literal interpretation of Bereishis, in which we have a young earth. But while it is possible to say that the count of 6000 years was from the time of Adam, it is no longer so compelling. What were the 2000 years of Tohu, and why weren't the preceding years reckoned? How was Bilaam standing in the middle of earth's time? No, it seems as if this 5000/7000 year prediction is predicated on a young earth.
The solution may well be that these interpretation, indeed, are incorrect. And if so, it would not be the first messianic prediction, even made by a member of Chazal, which has fallen flat. (What happened with Rabbi Akiva and Bar Kochba?)
If so, that does not mean that mashiach will not arrive, or that the world will not at some point end. That will arrive whenever it does arrive.
In terms of mashiach, ואף על פי שיתמהמה עם כל זה אחכה לו