A Siyum Hashas is the celebration held after one has completed learning the entire (Babylonian) Talmud.

Siyum is Hebrew for “completion” or “closing.” When someone completes a course of Torah study—finishing a tractate of Talmud or another significant text—they celebrate this milestone. This celebration is typically known as a siyum. This practice dates back (at least) to the Talmudic era. For example, we read the Talmud that whenever the great sage Abaye would see a young Torah scholar who had completed studying a tractate, he would make a feast for his colleagues.

Shas is an acronym for shisha sedarim, “six orders” of the Mishnah, the foundational text of the Talmud. In common parlance, when one studies Talmud we say he is “learning Gemara,” but when speaking of the work as a whole, it is often referred to as Shas, since it encompasses teachings on all six orders of the Mishnah.

Thus, when celebrating the milestone of completing all 2,711 folios of the Babylonian Talmud—an accomplishment that can take an entire lifetime—we call it a Siyum Hashas.

Learning one double-sided page a day, this effort takes around seven and a half years. Learning seven pages a day (which would take several hours for a seasoned scholar), it would take just over a year.

Now, many people do not have the ability to study the entire Shas. Yet they too can make a siyum. Here’s how: Every year, Chabad-Lubavitch communities divide up the entire Talmud, each individual studying another tractate and celebrating a grand communal siyum when the effort is complete.

This custom was established by Rabbi Schneur Zalman of Liadi, the first Chabad rebbe. It is a longstanding tradition that the division takes place on Yud Tes Kislev, celebrated as “the New Year of Chassidus.”

The Rebbe—Rabbi Menachem M. Schneerson, of righteous memory—once explained the appropriateness of this date: Although comprised of many seemingly disparate parts, the entire Torah is essentially one entity. This wholeness of Torah is achieved only by the combination of the revealed and hidden elements of Torah, represented by the Talmud and Chassidism, respectively. Thus it is natural that the Siyum Hashas was established on the 19th of Kislev, when Chassidism is celebrated.

Want to start learning toward your own Siyum Hashas, or need help with mastering the tractate you took for your communal siyum? Here is an ever-growing collection of classes on the Talmud by Rabbi Avraham Meyer Zajac.