Pirkei DeRabbi Eliezer, a fascinating and sometimes enigmatic text, sheds light on this very question. It tells us that the sun marks the days, and the moon the nights, their cycles an eternal promise: "they shall not cease." But it's not just about observing these celestial bodies; it's about understanding their movements, and aligning our calendar with them. This is where the concept of ibbur shanah, the intercalation of the year, comes in.

Imagine a secret, entrusted to a select few. Noah, after the flood, passed this knowledge to his son Shem. Shem, according to this tradition, was initiated into the principles of intercalation – adding an extra month to the calendar to keep it aligned with the seasons. Because of his knowledge and his service "by day and by night," Shem was called a priest, a Kohen, just as it says, "And Melchizedek king of Salem… was a priest of God Most High" (Genesis 14:18). Now, was Shem actually a priest? The text clarifies that it's because of his firstborn status and his dedicated service that he earned this title.

And the story continues. Shem, in turn, passed this tradition to Abraham. He, too, mastered the art of intercalation and was also called a priest, as we find in Psalm 110:4: "The Lord hath sworn, and will not repent, Thou art a priest for ever after the order of Melchizedek." The phrase "after the order of Melchizedek" is our clue, connecting Abraham back to Shem and the unbroken chain of knowledge.

Abraham entrusted this knowledge to Isaac, and after Abraham's death, Isaac continued the practice of intercalating the year. Genesis 25:11 tells us, "And it came to pass after the death of Abraham, that God blessed Isaac his son," and the text explains this blessing as a direct result of Isaac's mastery of intercalation, a "blessing of eternity."

Finally, Isaac passed the tradition to Jacob. But here, we encounter a fascinating twist. Jacob, while outside the Land of Israel, attempted to intercalate the year. But the Holy One, blessed be He, stopped him! "Jacob! Thou hast no authority to intercalate the year outside the land," He said. As we read, "And God appeared unto Jacob again, when he came from Paddan-Aram, and blessed him" (Genesis 35:9). Why "again"? Because the first time, God prevented him. Only when he returned to the Holy Land could Jacob resume this sacred task.

This highlights a crucial point: the intercalation of the year, this vital act of maintaining the calendar, was intrinsically linked to the Land of Israel. Even when the Israelites were exiled to Babylon, they still relied on those remaining in the Land to determine the calendar. And when all were exiled, they intercalated in Babylon, a temporary measure.

Even Ezekiel, a major prophet, wasn't allowed to intercalate the year in Babylon when Ezra and the community returned to the Land. God tells him, "Thou hast no authority to intercalate the year outside the Land; behold, Israel thy brethren, they will intercalate the year," (Ezekiel 36:17).

This principle is emphasized: Even if the wisest and most righteous individuals are outside the Land, the authority to intercalate the year rests with those within it – even, the text somewhat shockingly says, with "the keeper of sheep and herds" or "the ignorant." Why? Because the connection to the Land is paramount. "Son of man, when the house of Israel dwell in their own land," Ezekiel states, "it is their duty to intercalate the year."

This passage from Pirkei DeRabbi Eliezer isn't just a historical account; it's a testament to the enduring connection between the Jewish people, the Land of Israel, and the cycles of time. It reminds us that even in exile, our hearts and minds were always turned towards the Land, towards the possibility of return, and towards the restoration of our traditions in their rightful place. And it makes you wonder, doesn't it? What other ancient wisdom is waiting to be rediscovered, waiting to illuminate our understanding of the world and our place within it?