A weekly feature of Torah Tidbits to help clarify practical and conceptual aspects of the Jewish Calendar, thereby better fulfilling the mitzva of HaChodesh HaZeh Lachem...

This Shabbat we bench Rosh Chodesh Tevet, which will be on Thursday and Friday of Chanuka.

ROSH CHODESH TEVET Y'H'YEH B'YOM CHAMISHI U'V'YOM SHISHI HABA ALEINU V'AL KOL YISRA'EL L'TOVA.

This is the only Rosh Chodesh on which we say whole Hallel (because of Chanuka, of course). This is counter-balanced by Rosh Chodesh Tishrei, on which no Hallel is said (because of Rosh HaShana).

The Molad of Tevet will be on Wednesday morning, 56 minutes and 12 chalakim after 5:00.In clock time, that's about 5:36am Israel Standard time. The actual Molad is several hours earlier, 12:32am on Wednesday.

What this means, is that the Moon is likely to be visible on Thursday evening, which would mean that if we had a Sanhedrin today, they would probably proclaim Friday as Rosh Chodesh. We'd actually match up this month.