The Divided Jewish Calendar

Science and Health

In his introduction to the Shemirat Shabbat Kehilchatah, Rabbi Yehoshua Neuwirth writes about his experiences as a teenager during World War II, when he and his family hid inside a cramped attic in Amsterdam. He writes that:

…we also had no calendar by which we could know the dates of the holidays. Through a Kitzur Shulchan Aruch (which I received from my older brother Simcha Elazar, of blessed memory, who was deported along with his Yeshiva in France in 1942 and murdered in Auschwitz), I managed to learn how to calculate the Hebrew calendar. Based on that, I created a calendar for the years we stayed in hiding. This calendar included the dates of Sabbaths, holidays, and fast days, providing a Hebrew date for every day of the war.….The Jewish underground heard about this calendar and copied it, and ensured it was available for the Jewish refugees in hiding. After the war, the halachic calculation I used was found to be accurate. (I still have that calendar in my possession today).

A fifteen-year-old boy being hunted by the Nazis uses the few scraps of paper he has to write out a painstakingly researched Jewish calendar. What motivated him to do this?

The calendar stands at the very heart of Judaism. Sacred time organizes the entirety of the year with mathematical precision. Shabbat is the seventh day. The major festivals, Pesach and Sukkot, have seven days. (Sukkot has an additional eighth day, Shmini Atzeret, as well.) There are seven weeks of seven days in the Omer count. Within the holidays, as the Vilna Gaon points out, the number of days when work is mostly prohibited are six; with a seventh holiday, Yom Kippur, having a total prohibition of work, just like Shabbat. Sacred time is embedded into God’s creation, the equation for a spiritual life.

Sacred time allows us to experience, as Rabbi Joseph B. Soloveitchik described it, “time as grounded in the realm of eternity.” Time is not merely a physical measure, a straight line moving from one point to another. The present is always in dialogue with the past and the future. Historical events are the basis of the Jewish holidays. By remembering them, we connect to a “unitive time consciousness”; what once occurred can be reexperienced again, and transform our present.

Young Yehoshua Neuwirth understood this; he realized that a Jewish calendar could offer a taste of transcendence and raise him high above the dark attic he was trapped in.

The Jewish calendar has many inspirational holidays. But what is unclear is how, or even whether, the various holidays of the year integrate together.

Kabbalists have interpreted the various holidays as reflecting different aspects of the sephirot, the divine connection to this world; together, the holidays bring an integrated system of divine influence into the temporal world.

Rabbi Samson Raphael Hirsch offers a fascinating explanation of this question in Horeb. He explains that the holidays are meant as ongoing reminders to reconnect to our mission, and that “The common factor of all these days is that they all interrupt our active life … to contemplate the truths lying at the foundation of our existence.”

Hirsch outlines each holiday’s message; these ideas are found in three pairs. Shabbat, the day of creation, teaches us about the “consecration of life.” Pesach, the day of the Exodus, represents the “physical creation of the nation.” Shavuot, when the Torah was given, represents the “spiritual creation of the nation.” Sukkot represents the “physical survival of the nation,” while Shemini Atzeret reminds us of the “spiritual survival of the nation.” Finally, Rosh Hashanah and Yom Kippur reinforce the lessons of Shabbat and teach us to embrace the continued “examination of life.”

Together, these holidays create a unified, harmonious calendar. The holidays are scheduled maintenance for the soul, lessons that must be regularly reviewed.

Parshat Emor divides the calendar into two halves, with 44 verses in this section (Vayikra 23). The first 22 verses focus on the Shabbat, and the holidays in, or connected to, the month of Nissan: Pesach, the Omer, and Shavuot. The second 22 verses are about the holidays of Tishrei: Rosh Hashanah, Yom Kippur and Sukkot. Elchanan Samet has demonstrated the multiple linguistic parallels between the two halves; they stand apart, yet mirror each other.

The division of the holidays in Vayikra 23 into two equal sections offers a provocative possibility: Perhaps the Jewish calendar is divided into competing halves.

This competition becomes apparent in a debate in the Talmud. Although we generally refer to Rosh Hashanah as the day of creation, it is actually a matter of dispute. Rabbi Eliezer says the world was created in Tishrei, and Rabbi Yehoshua says it was created in Nissan.

This debate is not merely about creation. It is about which month is the primary month of the Jewish calendar. Rabbi Eliezer says that the future Messianic redemption will occur in Tishrei, while Rabbi Yehoshua says it will occur during Nissan, just as it did during the Exodus.

Unlike Rabbi Yehoshua, Rabbi Eliezer considers Tishrei to be the most important month, when the future redemption will occur.

But what provokes this debate between Rabbi Eliezer and Rabbi Yehoshua? What defines the difference between Tishrei and Nissan?

Nissan is a time of miracles. God himself redeems man from Egypt; and just 50 days later, he appears to the Jewish people on Mount Sinai. Rabbi Yehoshua sees this miraculous month as exactly where the beginning of the world and the end of history should take place.

In Tishrei, man is the protagonist. On Rosh Hashanah, man stands before God, praying, repenting, and working on developing the best version of himself. On Sukkot, we remember a story of human resilience, how the Jews survived the desert in rickety huts they built themselves.

This is why Rabbi Eliezer sees Tishrei as the central month; in his view, the future redemption is not automatic. It will only occur if the Jews repent. The ultimate fate of God’s creation is in the hands of man.

Vayikra 23 recognizes the difference between the two types of holidays by dividing them into two sections.  God is the protagonist in Shabbat, Pesach, and Shavuot; man takes the lead in Rosh Hashanah, Yom Kippur, and Sukkot. But the sections are of equal length, a clear indication that they contain equal value.

Rabbi Yehoshua and Rabbi Eliezer may debate whether God or man play the starring role in the holidays; but the Torah wants us to hold on to both views, to embrace a dual calendar divided in two.

This dual Jewish calendar is not harmonious; but it offers a 3-D vision of life, where we must both have faith and take responsibility.

Life brings moments when God seems distant, and we must work furiously to do what we can on our own. And then there are moments when we are powerless, and all we have left is faith.

The dual Jewish calendar reminds us that when all seems lost, sometimes God will step in, and sometimes man will step up.

And it is in those in-between moments that miracles will happen.


Rabbi Chaim Steinmetz is the Senior Rabbi of Congregation Kehilath Jeshurun in New York.