Q. When is the night of Nitel this year? Why do some people avoid learning Torah? Does it have to be kept?
A. Nittel Nacht is the night of Dec 24. On question 2491 regarding not learning Torah on the Nit’l night, we wrote:
“This day actually marks the birth of 'Oisso Hoish' (Yeshu or Yoshke) and it coincides more or less with the winter solstice. Historically it goes back many centuries, as it was the occasion of pagan festivities such as Saturnalia.
Later on, the Church, as it often did, adopted it and made it coincide with the birth in Betlechem of Yeshu and the celebration of Christmas, better known in our tradition as the night of 'Nittel.' From the term for natalis or being-born in Latin. Or as some argue, it represents the first letters of Nolad Yeshu Tes Leteves. Yeshu was born on the ninth of Teves. (Nitei Gavriel – Chanuka p. 416).
Since the event, turned out to be catastrophic to our nation, giving rise to all kinds of severe persecutions, inquisitions and many a holocaust, it was therefore established as a day of mourning and fasting. The fact that the reason was hidden and deemed forgotten or was disguised by Ezra's yortzait, was simply to avoid further conflict with the Church, that would only increase their antisemitism and abuse. See question 2489 above.
This day follows the Eight of Teves, also a time for fasting mentioned in Shulchan Aruch (ibid.). It marks the day the Torah was translated into Greek. This gave rise to false and mendacious interpretations of the text, and thus made possible and gave authority and validity to the New Testament.”
However, the corresponding Hebrew calendar dates change from year to year.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a