“Luach Kolel Chabad,” published for the first time almost 100 years ago, is republished every year with relevant updates. The need for such a luach, the Rebbe explained, was to address shailos – or to inform that there is a shaila to begin with.
The Luach Kolel Chabad, the familiar staple in every Lubavitch shul, was written by the great Chabad posek Reb Avrohom Chaim Noeh. His son, Reb Boruch, republished it every year, updated with corrections and annotations.
Unofficially, the Rebbe was actively involved. There were years when the Rebbe actually edited the Luach and communicated with the editors over its content.
During the last Rosh Hashana Farbrengen that we merited, in 5752, the Rebbe brought up the Luach:
“With all the changes in davening and minhagim of yom tov, it is imperative to learn the necessary halachos in Shulchan Aruch for these days. Alternatively, as has lately become the custom, to look at a luach, for example the Luach Kolel Chabad.”
Here the Rebbe explained its importance:
“It is actually important to memorize the Luach by heart. Because sometimes a person is in a situation when he is not permitted to talk, or there is no one at hand to ask, or worse: sometimes one doesn’t realize there is a shaila at all to be asked…”
(Noda Bashiurim ch. 25; Sichos Kodesh 5752 p. 21)
From The Weekly Farbrengen by Merkaz Anash