Halocho # 450 - How many days are there in Marcheshvan and Kislev?

Some years the Jewish calendar has 12 months, the rest (7 out of 19) are leap years with 13 months.

Jewish months alternate between being 29 and 30 days long.

However, the months of Marcheshvan and Kislev sometimes both have 30 days (a full year), sometimes both have 29 days (a missing year) and sometimes follow the regular order with Marcheshvan having 29 days and Kislev 30.

As a result, Chanukah (which starts on 25 Kislev and lasts 8 days) sometimes ends on 2 Tevet and sometimes on 3 Tevet.

This year is a "full" year; Marcheshvan has 30 days, Kislev has 30 days and Chanukah ends on 2 Tevet.

Source: Kitzur Shulchan Aruch 221:4

Chodesh Tov

- Danny
Monday, Erev Rosh Chodesh Kislev, 29 Marcheshvan 5770