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...
The Molad of Tevet was last Friday night (Dec 18), 21h 8m. That is 8:47pm Israel time. (The actual Molad was later that night at 12:41:35am. The moon was first visible on Sunday evening.)
Minhag Yerushalayim follows the opinion that Kiddush L'vana can (and should) be said from three days (72 hrs.) after the molad. That would be Monday, from 8:47pm. By that time, the Moon had already set, so the first opportunity for K.L. this month was Tuesday night, December 22nd.
For those who follow the 7-day rule and or Motza'ei Shabbat, the best time for K.L. this month will be Motza"Sh (Vayigash, Dec. 26th).
As I have often said (and written), K.L. is a particularly special and beautiful mitzva that comes our way monthly. It sometimes takes extra effort on our part to fulfill it, especially during the winter. But it's worth it.