Of all the Rebbe’s works and teachings, perhaps the most commonly consulted and perused among his followers is the chassidic calendar, Hayom Yom - literally “today is the day,” which he compiled on the behest of his father-in-law in the winter of 1942-3.1

The calendar begins on the 19th of Kislev, the date marking the release of Chabad’s founder, Rabbi Schneur Zalman of Liadi, from Tsarist imprisonment. Rabbi Schneur Zalman was accused of starting a new religion, of sowing subversion among Jewish youth and of threatening the sovereignty of the Tsar. His vindication, by express order of the Tsar himself, was taken as a sign from heaven that he and the chassidic movement as a whole had also been vindicated in the heavenly court. This date is celebrated in Chabad as “the festival of redemption,” and the fifth rebbe, Rabbi Shalom DovBer of Lubavitch, went so far as to call it “the New Chassidus is vitality, bringing life and illuminating everything, even the undesirable... in order to correct it.Year for chassidism.”2

The Jewish calendar and its festivals endow the passing days and seasons with a cycle of significance prescribed by Jewish law. Rabbi Shalom DovBer’s statement implied that the cycle of time could be further infused with a uniquely chassidic quality. By instructing R. Menachem Mendel to create a calendar beginning from this date R. Yosef Yitzchak took a previously abstract concept and made it concrete.

What is the nature of this uniquely chassidic quality? How can it be infused into the daily cycle of life?

The answer to the first question is found in Hayom Yom itself. In the entry for the 24th of Tevet R. Menachem Mendel quotes his father-in-law:

My grandfather [Rabbi Shmuel of Lubavitch] asked the Tzemach Tzedek [Rabbi Menachem Mendel of Lubavitch]: What did Grandfather [Rabbi Schneur Zalman of Laidi] wish to achieve with “the ways of chassidus” and what did he wish to achieve with [the teachings of] chassidus?

The Tzemach Tzedek answered: “The ways of chassidus” are that all chassidim are to be like one family, with affection, as Torah teaches. Chassidus is vitality, bringing life and illuminating everything, even the undesirable... in order to correct it.

At the core of the vision behind Hayom Yom stand these two purposes, to encourage a familial feeling of belonging among all chassidim, and to illuminate the daily service of G‑d with fresh vitality. Accordingly R. Yosef Yitzchak The family of chassidim would be united through these quotas of common study, known collectively by the acronym chitas.requested that the calendar include “quotas of study equal for every individual… [emphasis added] 1) chumash with Rashi’s commentary, 2) Tehilim… as divided among the days of the month, 3) quotas of Tanya study as I have divided it for the days of this year.” The family of chassidim would be united through these quotas of common study, known collectively by the acronym chitas (חת”ת). R. Yosef Yitzchak further asked his son-in-law to compile “aphorisms from the teachings of chassidus and the ways of chassidus, short pieces for each of the days of the year.” These aphorisms and anecdotes, all of which are selected from Rabbi Yosef Yitzchak’s own talks and writings, provide refreshing insight, illuminating each day with special vitality.

Subsequent to Hayom Yom’s publication, R. Yosef Yitzchak penned an effusive review in a private letter:

This is a small format booklet - just as a chassid must be small in one’s own estimation - but it is packed with pearls and diamonds of the greatest and best quality. It is, thank G‑d, a true work of chassidic culture. G‑d… has so favoured my son-in-law, the rabbi and gaon R. Menachem Mendel, to be able to establish such a grand hall of chassidus… such that “each day declaims its statement.” Each day says something. It is the true Hayom Yom, each day is a day.3

The rest of the letter consists of an extended elaboration on the specific Hayom Yom entry of that particular day. For R. Yosef Yitzchak, the daily entry chosen by R. Menachem Mendel infused each day with special luminance, setting it apart from other days with a unique sense of significance and purpose. To this day, the Rebbe’s followers continue to follow the daily study quotas set out in Hayom Yom, and each year read anew the daily aphorisms that he chose.

The Rebbe would often emphasize that Torah is eternally relevant, eternally fresh, as our sages said, “each day it should be in your eyes as new.”4At every moment Torah provides us with the means to make our environment a spiritual one. But eternal novelty seems like a contradiction in terms. This paradox, the Rebbe pointed out, touches on a core tenet of Chabad chassidism: G‑d did not simply create the world at the beginning of time and leave it to run its course; at every moment G‑d recreates all existence from absolute nothingness. Through the lense of Hayom Yom this theological principle is turned into an injunction of poignant practicality:

G‑d created the universe and all physical objects ex nihilo, "something from nothing." Jews must transform "something into nothing." They must transform materiality into spirituality… This is an obligation upon every specific individual.5

At every moment G‑d is creating the material environment in which we find ourselves. At every moment Torah provides us with the means to make our environment a spiritual one.6