The question of whether or not Dec. 21 will be the end of the world has been a hot topic in the media. These speculations are based on the Mayan calendar coming to an end. This is not, however, the first time that the world has worried that the end was near.
There have been many who have claimed to have either deciphered or had a mystic revelation of the exact date of the end of the world (as we know it) and the coming of the final redemption. There have also been many who have declared themselves to be the Messiah -- the one who will bring about the ultimate redemption of humankind -- but have not lived up to their promises.
Although the concept of a Messiah* (Moshiach in Hebrew) and an end to the world as we know it is not overtly mentioned in the five books of the Torah, it is actually one of the fundamental articles of Jewish faith. As Rabbi Moses ben Maimon (Maimonides/Rambam) included in his 13 Principles of Faith (as popularly rendered): "I believe with perfect faith in the coming of the Messiah; and even though he may tarry, nevertheless, I wait each day for his coming."
The Torah does, however, describe the future that will befall the Jewish people when (not if) they turn their hearts from the Torah (Deuteronomy 28): The land will be destroyed, the people ravaged by disease before being defeated by enemies and exiled. These events have, sadly, come to pass, repeatedly.
Two chapters later, however, Moses informs the people that after all of the curses have befallen the Children of Israel and they have returned to Him with all their heart and soul, then the curse will be undone. This chapter includes all of the famous promises of the ultimate redemption: Ingathering of the exiles, return to the land and the destruction of Israel's enemies. While this process has started several times in the history of the Jewish people, it has never been completed. Jews have returned to Israel, but never in peace and never as an entire people.
Many of the details of the time of the redemption are encrypted in the books of the Prophets. Isaiah, in particular, contains a great number of references and is the primary source from which it is understood that the Messiah, the one destined to lead the Jewish people to their ultimate redemption, will come from the Davidic line. "And there shall come forth a rod out of the stem of Jesse (King David's father), and a branch shall grow out of his roots: And the spirit of the Lord shall rest upon him" (Isaiah 11:1-2).
As fascinating as end-of-days prophecies and the coming of the Messiah may be, the Torah's only apparent reference to a time when redemption will come states: "And it shall come to pass, when all these things are come upon you, the blessing and the curse, which I have set before you, and you shall bethink yourself among all the nations, where the Lord your God has driven you" (Deuteronomy 30:1).
Trying to calculate the exact date of the final redemption is not a high priority for most Jewish scholars. Perhaps that is because Jewish law focuses on the here and now (which is the same reason for the unexpectedly vague discussions of the afterlife).
The Talmud states that "Seven things are hidden from humankind ... [one of them being] when the Davidic dynasty [the Messiah] will return; and when the wicked kingdom will come to an end" (Pesachim 54b).
Nevertheless, we do have some information about the coming of the Messiah. For instance, "Rabbi Kattina said: The world is to last six thousand years, and [for] one thousand it will be desolate" (Rosh Hashana 31a). Now, before one sits down to try to calculate those years (keeping in mind that the Hebrew year is 5763), it is important to consider the following statement by Rav: "All the predestined dates [for redemption] have passed, and the matter [now] depends only on repentance and good deeds" (Sanhedrin 97b).
Rav's statement not only supports the fact that humankind is unable to calculate the date of the coming of the Messiah and the end of the known world, but demonstrates that Judaism is fundamentally about the here and now.
*While the term Messiah is used for savior, it literally means "anointed one."