Rosh Chodesh on Sun and Mon

Question:

Hi, is Rosh Chodesh Sunday and Monday this December (2024)? If so, is there Yom Kippur Katan given it is Shabbat? What is done? Is it another day?

Answer:

Hello,

When erev Rosh Chodesh is on Shabbos, then Yom Kippur Katan is on Thursday, two days earlier.

Best wishes