People living overseas are much more familiar with the last part of the Portion of Re’eh than people living in Israel. The reason is that these verses make up the Torah reading for both the eighth day of Pesach and Shemini Atzeret, two holidays that do not exist in Israel. The verses review all of the holidays other than Rosh Hashanah and Yom Kippur. Having grown up overseas, it is only natural that when reviewing the portion in preparation for this essay, one of these verses popped into my head [Devarim 16:1]: “Observe the month of spring (Aviv) and offer a Passover sacrifice to G-d, for it was in the month of spring (Aviv), at night, that G-d freed you from Egypt.”
At first glance, the last word of the verse – night (layla) – seems extraneous. What does the exodus occurring at night have to do with our celebrating Pesach in the spring? Before we continue, some background is necessary. The Jewish calendar is based on the lunar calendar. The moon orbits the earth once every twenty-nine and a half days or so. One lunar year consists of twelve lunar (synodic) months, or about 354 days. One solar year, the time it takes the earth to complete one orbit around the sun, is about 365.25 days. This means that each solar year, the lunar year slips backwards by more than eleven days. Around thirty-two years are required for the lunar and solar years to resynchronise.
This backward slippage is a built-in feature of the Islamic calendar. The Egyptians refer to the Yom Kippur War, fought in October 1973 (Tishrei 5733), as the Ramadan War, as it occurred during the month of Ramadan. This year, the month of Ramadan began in April. Ramadan will not coincide with the month of Tishrei until 2038. The Talmud in Tractate Rosh Hashanah [21a] locks this feature out of the Jewish Calendar, interpreting the Torah’s commandment to “observe the month of spring” as a directive to ensure that Pesach always falls in the spring. More specifically, we must ensure that Pesach, which falls on the fifteenth day of the month of Nissan, must fall on the first full moon after the spring equinox. In order to ensure that the lunar calendar remains synchronized with the solar calendar, every so often a leap year is required and an additional thirty-day month of Adar is inserted into the calendar, pushing Pesach back into the spring.
In a perfect world, leap years are determined by the Jewish High Court, or, the Sanhedrin. About 1600 years ago, the Roman Emperor, Constantius II, following the precedents of Hadrian, abolished the Sanhedrin and with it, our capability to manage the calendar. To ensure that the Jewish People would always celebrate Pesach in the spring, Hillel II took upon himself to calculate an authorized calendar which would determine the Hebrew date until the cessation of the religious persecution that had shut down the Sanhedrin. Hillel’s calendar is based on the Metonic Cycle, first discovered by Meton of Athens in the fifth century before the Common Era. The Metonic Cycle is a nineteen-year cycle – 6,940 days – in which the moon returns to exactly the same place at the same longitude and against the same constellation in the sky with the same phase. A corollary of the Metonic Cycle is that if seven leap years are inserted every nineteen years, the solar and lunar calendars will resynchronise.
Why is it so critical that Pesach fall in the spring? Pesach celebrates the exodus of the Jewish People from Egypt. Pesach celebrates the creation of an independent Jewish nation. Pesach celebrates birth. The conceptual connection between birth and the spring does not require a tremendous amount of imagination. In Israel, winter is the rainy season. By the time the winter is over, around Pesach time, the entire country is bathed in a lush hue of green. Flowers are in bloom. New potential hangs in the air. According to the Talmud in Tractate Rosh Hashanah [12b], the future redemption will also take place in the spring. King Solomon presented this majestically in the Song of Songs [2:12]: “The blossoms have appeared in the land, the time of pruning has come; The song of the turtledove is heard in our land.” Our Sages in the Midrash interpret this entire verse as an allusion to the future redemption, in which the “song of the turtledove” is a metaphor for the Messiah. This does not preclude a fall, winter, or summer redemption, but nevertheless, whenever the final redemption does occur, it will be accompanied by endless blossoms.
Taking this metaphor one step further, the occurrence of the exodus in the dark of night fits in quite nicely. Up until the moment of their exodus, the Egyptian Jews suffered in abject servitude. When G-d killed the Egyptian first born, the sun rose at the stroke of midnight. Darkness turned to light, the snow melted, and for the Jewish People, spring had sprung.
I would like to suggest an alternate explanation that, while retaining the night-equals-exile motif, takes things in a completely different direction. In order to understand this explanation, we must return to Meton. The Metonic cycle works by assuming that the lunar month is 29.5 days and the solar year is 365.25 days. But these are only approximations. The length of one synodic month is not 29.5 days – it averages 29 days, 12 hours, 44 minutes, and 3 seconds. The length of one solar year is not 365.25 days – it is closer to 365 days 5 hours 48 minutes 46 seconds. Performing some simple mathematical calculations shows that over the course of one Metonic cycle, the lunar year slips by two hours to the right. While this might not seem like a lot of time, each (12 x 19) 228 years, the Jewish calendar moves away from the Gregorian calendar by one full day. Since Jews began using the calendar of Hillel II, about 85 Metonic cycles have passed and the Jewish and Gregorian calendars have diverged by more than a week. Pesach is falling later and later. In another three hundred years, in 2323, most of Pesach will fall in the month of May. This is not only a problem for our descendants – it is our problem, as well. In two years, in 5784 (2024), Pesach will fall on the night of April 22, the second full moon after the spring equinox. If it were up to a Sanhedrin, 5784 would not be a leap year and Pesach would fall on the night of March 24, the first full moon after the spring equinox. Instead, on March 24, Jews will be celebrating the holiday of Purim.
Any person who has spent enough time overseas will notice that Easter Sunday nearly always coincides with Pesach. This is because the date of Easter is calculated using the identical equation mandated by the Talmud in Tractate Rosh Hashanah for calculating when to create a leap year: The date of Easter according to the Catholic and Protestant Churches is the first Sunday after the full Moon that occurs on or after the spring equinox. If the full Moon falls on a Sunday then Easter is the next Sunday. The only time that Easter does not fall on Pesach is when Pesach falls one month later than it should because of the drifting of the calendar of Hillel II. In 5784, while Jews will be celebrating Pesach on April 22, the Christians will be celebrating Easter almost one month earlier, on March 31.
The problem is that as far as the Talmud is concerned, the Christians have it right and the Jews have it wrong. Sometimes we are celebrating Pesach one month later than we should. This is an embarrassment. Because of the darkness of the night of our exile, we are not celebrating Pesach in the spring. The solution is the reinstatement of the Sanhedrin and a return to human determination of leap years. We do not have to wait for the Messiah. The reinstatement of the Sanhedrin is not contingent upon redemption. Its creation hinges on a modicum of Jewish unity. If we can overcome the petty political and religious issues that divide us, then we can turn night into day.
Ari Sacher, Moreshet, 5782
Please daven for a Refu’a Shelema for Yechiel ben Shprintza, Geisha bat Sara, Hila bat Miriam and Batya Sarah bat Hinda Leah.
 In Israel, Shemini Atzeret is bundled together with Simchat Torah.
 The fifteenth day of a lunar month corresponds to a full moon.
 The joint dependence of the Jewish calendar on both the sun and the moon transforms it into a hybrid “lunisolar” calendar.
 This is why our Hebrew birthdays and our Gregorian birthdays usually coincide every nineteen years.
 19 solar years – 228 synodic months – (7 x 30)