Double fresh, double good, come on and double it

Shavua tov! This post is in honor of Parshat Matot-Mas'ei, which is read in the coming week. These two portions are almost always read together. The motivation behind this post is a tiny piece of the larger goal of creating empowered Jewish communities: if our communities are empowered, then we shouldn't be unnecessarily dependent on anyone else. Among other things, this means that if we're stuck in the wilderness and don't have access to the Jewish calendar from the funeral home, we should be able to generate one on our own. Therefore, here is:

The Mah Rabu Guide to Single and Double Torah Portions

The basic idea: The Torah is divided into 54 portions. The last one (Vezot Haberachah) is only read on Simchat Torah when completing the Torah, and is never read on a regular Shabbat. So call it 53 that have to be distributed across the regular Shabbatot of the year. A non-leap year has 353-355 days (50-51 weeks), and a leap year has 383-385 days (54-55 weeks). But the regular Shabbat reading is never read if the Shabbat happens to be a holiday. It differs from year to year whether a given holiday falls on Shabbat, but there is always at least one Shabbat during Sukkot and one during Pesach. This means that the total number of non-holiday Shabbatot in a given year can range from 46 to 53. To address this, anywhere from 0 to 7 sets of Torah portions are doubled up.

So the general principle behind these rules is that any time an extra (non-holiday) Shabbat is added, a pair of Torah portions is read individually, and any time a Shabbat is removed, a pair of Torah portions is read together.

• Vayakhel-Pekudei
• Tazria-Metzora
• Acharei Mot-Kedoshim
• Behar-Bechukotai

In general, these four pairs are read as double portions in a non-leap year, and read separately in a leap year. This accounts for the 4 extra weeks added in a leap year. These don't start until Adar, because before Adar it "isn't yet known" whether the year will be a leap year.

Exceptions: In a non-leap year that begins on Thursday, an extra Shabbat is squeezed in, because Simchat Torah at the beginning of the year is on Thursday (or Friday), right before Shabbat. There are two such types of years. In a 355-day year beginning on Thursday (i.e. the following year begins on Tuesday), Vayakhel and Pekudei are read separately to cover the extra Shabbat. In a 354-day year beginning on Thursday (i.e. the following year begins on Monday), communities that observe 2 days of yom tov don't need to worry (and all 4 of these pairs are read as double portions) because the 8th day of Pesach takes up one Shabbat. However, in this type of year, communities that observe 1 day of yom tov read Behar and Bechukotai separately. This means that 1-day and 2-day communities are reading different Torah portions for several weeks after Pesach.

• Chukat-Balak

This is read as a double portion whenever the 2nd day of Shavuot falls on Shabbat. (This means that Chukat-Balak is never read as a double portion in communities that observe 1 day of yom tov. The 1st day of Shavuot never falls on Shabbat.) This also creates a disparity between 1-day and 2-day communities for several weeks.

• Matot-Mas'ei

This is almost always read as a double portion (and without exception in non-leap years).

Exception 1: In a leap year beginning on a Thursday, Matot and Mas'ei are read separately, for the same reason discussed above (there is an extra Shabbat in the year).

Exception 2: In a leap year in which the following year begins on a Monday, there is also an extra Shabbat at the end of the year. In 2-day yom tov communities, this extra Shabbat is absorbed by the 8th day of Pesach (as above), so Matot-Mas'ei is combined as usual. However, in 1-day yom tov communities, Matot and Mas'ei are read separately. In these rare cases (covering about 10% of all years), the 1-day and 2-day calendars disagree for about 3 months (rather than just for a few weeks, which happens in 29% of years due to Shavuot and 18% of years due to Pesach).

• Nitzavim-Vayeilech

This is read as a double portion iff Rosh Hashanah or Yom Kippur falls on Shabbat, taking away a Shabbat from the regular Torah reading cycle.

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Now here's the shorter version which may be easier to remember, and covers most cases:

• Vayakhel-Pekudei / Tazria-Metzora / Acharei Mot-Kedoshim / Behar-Bechukotai: always separate in leap years; usually combined in non-leap years
• Chukat-Balak: combined if the 2nd day of Shavuot is on Shabbat
• Matot-Mas'ei: usually combined
• Nitzavim-Vayeilech: combined if Rosh Hashanah or Yom Kippur is on Shabbat