Yahrtzeit of Rabbi Yitzhak Blazer (1837-1907), a leader of European Jewry prior to World War I and the author of Pri Yitzhak. At a young age, he became the rabbi of St. Petersburg, a position he held for 16 years. He was one of the leading disciples of Rabbi Yisrael Salanter, the founder of the Mussar ethics movement. Rabbi Blazer spent the last few years of his life in Jerusalem.