Tevet 5 is celebrated as a day of rejoicing in the Chabad-Lubavitch community. On this date in 1987, U.S. Federal Court issued a decision in favor of Agudas Chassidei Chabad ("Union of Chabad Chassidim") regarding the ownership of the priceless library of the 6th Rebbe of Chabad-Lubavitch, Rabbi Yosef Yitzchak Schneersohn. The ruling was based on the idea that a Rebbe is not a private individual but a communal figure synonymous with the body of Chassidim. The Lubavitcher Rebbe (Rabbi Yosef Yitzchak's son-in-law and successor) urged that the occasion be marked with time devoted to study from Torah books ("sefarim") as well as the acquisition of new Torah books.
Links:
Learn more about Hey Tevet
Watch: A Movement on Trial
The Rebbe's Library
A container is defined by its contents: A pitcher of water is water. A crate of apples is apples. A house, too, is defined by what it contains.
Fill your house with books of Torah, and your house becomes a Torah. Affix charity boxes to its walls, and your house becomes a wellspring of charity. Bring those who need a warm home to your table, and your house becomes a lamp in the darkness.