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Adding one minute to the conclusion of Rosh Hashanah:
The Rebbe Maharash related that in each generation of the Rabbeim they added one more minute to the conclusion of Rosh Hashanah. Thus by the Tzemach Tzedek, Rosh Hashanah concluded one minute later than it did by the Mittler Rebbe. By the Tzemach Tzedek, Rosh Hashanah concluded four minutes later than by the Baal Shem Tov. By the Mittler Rebbe it concluded three minutes later. By the Alter Rebbe it concluded two minutes later. By the Maggid it concluded one minute later. Every generation adds one minute. This is done in order to draw down Rosh Hashanah to the year.
 Sefer Hasichos 1945 p. 9-10; Otzer Minhagei Chabad p. 152