Due to a quirk of the Jewish calendar, there are no major holidays in the span of this Scroll. What an opportunity to talk about some quirks of the Jewish calendar! (Warning: math follows.)

The Jewish calendar is a lunisolar calendar, meaning primarily lunar, with months based on the recurring phases of the moon, but adjusted to keep in balance with the solar year, so that the holidays remain within their assigned seasons. Briefly, let’s make a simplifying assumption that each lunar month is thirty days: in that case, twelve months would make up 360 days (12×30). But, in fact, a lunar month is more like 29 1/2 days, and the calendar generally alternates between months of twenty-nine and thirty days. If we take off a half-day per month, or six days in total, we get 354 days per year, which is in fact the length of the basic Jewish year.

However, our calendar also accommodates the fact that certain occasions don’t interact well with Shabbat: specifically, Yom Kippur after Shabbat would interfere with Kol Nidre, Yom Kippur before Shabbat would prevent cooking and preparing for Shabbat, and Hoshana Rabbah on Shabbat would be unworkable. To prevent this, Rosh Hashanah may not fall on Sunday, Wednesday, or Friday, and the rest of the year falls in line accordingly. Technically, it’s the year leading up to Rosh Hashanah which lines up ahead of it, as the next two months, Cheshvan and Kislev, are “adjustable” so that both may be thirty days, adding one day to the year, or both twenty-nine, taking a day away, thus pushing or pulling the following year’s fall holidays into a permissible alignment. So the Jewish year can actually be from 353-355 days.

Perhaps you already see the problem: the solar year is (roughly) 365 1/4 days. This means every year, the Jewish calendar is ten to twelve days “short,” so the new year starts 10-12 days earlier, as do all the following holidays throughout the year. If we let this go on, every new year and all its holidays would come earlier and earlier on the civil calendar until eventually, about thirty-six years later, they would be a full year ahead and falling at about the same time of year as when we started. In fact, this is exactly how the Islamic calendar (a purely lunar calendar) works. This means, for instance, that an event that happened exactly 1000 years ago was about 1028 years ago on the Islamic calendar! This is confusing and inconvenient, but the bigger problem for our calendar is that our holidays are assigned to seasons, most importantly Passover in the spring, and in many cases to particular crop harvests, which in turn are tied to the seasons, which come and go as part of the solar cycle. How do we keep Passover from moving into a new season entirely every nine years or so?

The answer is that since the lunar calendar is ahead of the solar by about ten days every year, or about thirty days over three years, we can get it back in balance by adding an extra month of thirty days about every third year. In fact, since ten days is the minimal difference but the average is slightly higher, we add an extra month in seven years of every nineteen, so slightly more than one in three, following a particular pattern known as the Metonic cycle. Leap years, then, are 383-385 days. On those seven leap years in the cycle, such as this year, instead of making up an extra name for the additional month, we have two months of Adar. In such years, Purim is celebrated in the second Adar, hinting that it is the “real” Adar, as does the fact that First Adar is thirty days, while Second Adar, like “just” Adar in a regular year, is twenty-nine. Just to keep you on your toes though, yahrzeiten from “just” Adar are marked in First Adar on a leap year, so as not to appear to be postponing a mitzvah. In fact, leap years cause more complications in calculating mourning and yahrzeit than I have time and space for here; consult me directly for questions about yahrzeiten in Adar or counting mourning through a leap year.

Now, coming back to our starting point, I can explain that the period of this scroll covers almost exactly the months of Shvat and First Adar (aka Adar I) on the Jewish calendar. Shvat contains the minor holiday of Tu B’Shvat, often called the New Year (or the Birthday) of the Trees. While it has taken on a new significance in modern times as we more fully appreciate the role trees and plants play in our ecosystem, it’s still not a heavyweight among the holidays. Adar I doesn’t get Purim, but has to settle for Purim Katan, literally “Little Purim,” a kind of shadow Purim that acknowledges the calendrical ambiguity but has no real observances except for skipping tachanun, basically. Additionally, though not a holiday as such, we should acknowledge that this period on our calendar also includes the special Shabbat known as Shabbat Shirah (Shabbat of Song), the week when we read in the Torah of our biblical ancestors crossing the miraculously parted sea to escape the armies of Pharaoh, and of course singing the Song of the Sea on the other side.

Though quiet on the holiday front, this is an exciting stretch in our Torah reading schedule, as we’ll be reading all but the first and last parashot of Sh’mot (Exodus) over these couple of months. This means both great stories like the burning bush, the ten plagues, the Exodus itself, crossing the sea, revelation at Sinai, and the golden calf; and key theological pronouncements headlined by the Ten Commandments, to name just a few of many highlights. If you’re stir crazy at home, come join us in shul – if you’re snowed in at home, join us on Zoom. Stay warm, stay healthy, and see you soon!

Rabbi Boaz Marmon Saratoga Congregation Shaara Tfille