In a previous lifetime—well, it feels that way—I was a high school teacher in a Jewish school with separate boys and girls divisions. I taught Talmud to young men and Bible studies and Jewish history to young women.I occasionally amused myself by trying to fool my charges. Once, covering the medieval period in a girls’ class, I shared some piyut, or liturgical poetry, of the era and included among the offerings a translation into Hebrew I had done of a verse from Pink Floyd’s “Time.” I thought it lent itself to the style and substance of a medieval Jewish poem, and passed it off as one.The English verse went:“And you run and you run to catch up with the sun but it’s sinking;\nRacing around to come up behind you again.\nThe sun is the same in a relative way but you’re older,\nShorter of breath and one day closer to death.”I’ll spare you the Hebrew one.I had one of the girls read it to the class and I smiled to myself as I prepared to admit my little joke. But, before I had the chance, one savvy student suddenly erupted with a loud “Hey! That’s Pink Floyd!”Moments like that were what made teaching exhilarating. I confessed to my crime and that led to a class discussion about how time, indeed, as an array of Jewish commentaries have lamented, is so sad a reality. We can move about in space, but not in time. Relentless, it creeps, then glides, then (as we learn in later years) bolts forward, and we have no option of turning it back.Except we do, in a way.While we can’t ourselves actually travel back in time, Jewish theology asserts that we can reach into the past and change it. The time machine’s fuel is called will.Not any will, but a particularly pure form of the stuff: sincere, wrenching determination to change.The efficacy of that fuel is revealed in the Talmud, which explains that the process of teshuva, or “repentance,” can transform wrong actions committed intentionally, retroactively, into mere accidental acts. And it goes much further. When repentance is effected not through fear or less lofty means, but rather through pure love of God, it actually changes sins that were committed with full intent as sins into good deeds.A remarkable thought. Violating the Sabbath transformed into honoring it? Eating a cheeseburger into eating matzah on Passover? Engaging in gossip into reciting blessings? More than remarkable; it’s stupefying.Teshuva, in fact, literally means “returning.” That may be more than a metaphor about a present “return” to a purer state. It may be hinting to a “return” of a different sort, to, so to speak, the scene of the crime—in time. And the ability to tamper with the evidence, indeed with the crime itself.So, relentless though the march of years may be, Jewish tradition offers us the possibility of freeing ourselves, at least in a sense, from the subjugation of time.This tossing off of time’s shackles may be why the theme of freedom is so prominent on Rosh Hashana. The name of the month it introduces, Tishrei, is rooted in “shara,” the Aramaic word for “freeing”; the day’s central mitzvah, the sounding of the shofar, is associated with Yovel, or the Jubilee Year, when slaves are released; one of the holiday’s Torah readings is about Isaac’s release from his “binding”; and Rosh Hashana, in Jewish tradition. is the anniversary of Yosef’s release from his Egyptian prison.And freedom from time is prominent, too, in an absence on Rosh Hashana.There is a Jewish clock in the sky; we call it the moon. It is a symbol of the Jewish nation’s perennial rebirth, but it also keeps time for us. The sun may mark the passage of days for all humanity, but it is to the moon that Jews are commanded to look to identify the Jewish months.How intriguing that the Jewish timekeeper, which is prominent, usually full, on every other Jewish holiday, is entirely invisible on Rosh Hashana.