This is from January 2006.
My local Hasidic Rabbi took the night off last Friday night. He didn't speak before Kabalas Shabbos, and he didn't appear at his regular Friday night shiur. Why? Because it was Nittel Nacht, per the Greek Orthodox calendar, and on Nittel Nacht it is his custom to act like a mourner and forgo all Torah learning -- even on Shabbos.
A few notes on the practice:
1 - It's stupid. My local Hasidic Rabbi ignores July fourth. Memorial Day is not remembered. He goes to work on Thanksgiving. None of those days exist on his calendar. If he is going to ignore days that celebrate events from which he has benefited, how can he justify his recognition of Orthodox Christmas? Even a negative recognition is recognition. Memorial Day is not within a Hasid's ken; but Christmas is. That's topsy-tursvy.
2 - Orthodox Christmas? I understand the Rabbi's customs originated in lands where Orthodox Christmas is celebrated, but there are reasons for this custom and the most familiar reason does not adhere on on the sixth of January.
According to Miriam Shaviv, Hasidim abstain from Torah study because they "don't want to bring about such improvements [to the world through their Torah study] at a time when the Christian majority is devoutly steeped in their prayers, lest outsiders believe the improvement came from the Christian worship." Fabulous, only in America, Jan 6 is not a day of Christian prayer. If that's your concern, you should fast from Torah study on December 25 (or on Super Bowl Sunday when the betting halls probably contain as much prayer as any church)
A second justification for the custom is that often we dedicate Torah study to the memory of revered Rabbis and beloved ancestors. If we studied on Christmas, the argument goes, someone might mistake Jesus for a revered Rabbi. Worse, he might accrue credit on his heavenly account in the merit of our learning.
To the first concern I reply: Bwahaha. Not even the most degenerate Gop- Jew would mistake Jesus for a revered Rabbi. (I hope) To the second concern, I say "so what?" The real Jesus was a Jew who cared about other Jews. He had no intention of abolishing Judaism, or of establishing a church that would seek to destroy his people. If the clerk in charge of divine credit is stupid enough to think that my Christmas Eve learning is meant to be deposited on Jesus' account, I have no objection. (though I will suggest that the Almighty hire a clerk who doesn't have his head up his rear end)
3 - The common justification for the Heredi refusal to pause for the siren on Israeli Memorial day is that it is bitul Torah. Can you explain to me why two minutes to honor Israeli war dead is impossible, while a full night without learning has become accepted?
4 - The practice was unknown in Lita. The Chofetz Chaim, for example, learned on Christmas. Though perhaps those of Hasidic heritage can justify the practice on the grounds of "our ancestors did it so we should too" non-Hasidim have no excuse, and really should resist the temptation to embrace foreign minagim just because they look frum.
Search for more information about blasts from my past at 4torah.com.