30 Shvat -is the yahrzeit of Reb Menachem Mendel ben Reb Boruch Bendet of Shklov ZY"A. He was one of the most famous talmidim of the Gra ZY"A. Was know as an expert in Kabala. Made aliyah to Eretz Yisroel in 1808. Died in 5587-1827.
See here for more info. (At the bottom of the page)