The Gregorian New Year's Day (1 January) nearly always occurs in this month. Only rarely will it occur in either of the two neighbouring months (Kislev or Shevat).
Holidays
25 Kislev – 2 Tevet – Hanukkah (or 3 Tevet if Kislev is short)
5 Tevet is celebrated as a holiday by Chabad Hasidim, commemorating the 1987 verdict concerning an inheritance claim on the books of Rabbi Joseph Isaac Schneersohn.
↑"Day View". Shimon ben Shetach successfully completed the expulsion of the Sadducees (a sect which denied the Oral Torah and the authority of the Sages) who had dominated the Sanhedrin (Supreme Court), replacing them with his Torah-loyal Pharisaic disciples