Bar Mitzva and Yartzheits in a Leap-Year

Question: Our son was born in Adar and he turns thirteen during a leap-year. I was always under the assumption that he turns Bar Mitzva in Adar Sheni, but we were told to observe a relative’s yartzheit in Adar Rishon. Are they not the same?

Answer: There is a machlokes among the Rishonim as to whether ‘Adar’ during a leap-year generally refers to Adar Rishon or Adar Sheni. Rambam (Nedarim 10:6) writes that ‘Adar’ refers to Adar Sheni (See Kesef Mishna), while the Ran (Nedarim 63b) and Rosh (Nedarim 63a) write that it refers to Adar Rishon.

The Mishna Berura (427:3) writes that for the sake of clarity the chazan should ideally announce ‘Adar Rishon’ during mevarchim hachodesh.

When one’s relative passes away during one of the Adar’s in a leap year, the yahrzeit is observed during that same month in a leap year; either Adar Rishon or Adar Sheni. However, when one’s relative passes away during Adar in a non-leap year, there is a machlokes as to which month the yahrzeit should be observed in. The Shulchan Aruch (OC 568:7) writes that it should be observed in Adar Sheni. The Kaf Hachaim (OC 568:76) notes that this is the main Sefardi practice (See Bach YD 2201:12; Shach YD 220:16). Nonetheless, the Shulchan Aruch (CM 43:28) writes that in legal documents, it is presumed to be Adar Rishon.

The Rema (YD 402:12; OC 427:1; 568:7 quoting the Terumas Hadeshen 294; Mahari Mintz 9) disagrees, writing that it should be observed in Adar Rishon. (See Mateh Moshe 766; Chochmas Adam 171:11; Gesher Hachaim 32:10), though notes (OC 568:7) that some observe both (See Mishna Berura 568:42; Chassam Sofer OC 163; Tzitz Eliezer 22:39).

The Rema (OC 55:10) writes that a boy born in Adar in a non-leap year must wait until Adar Sheni to be considered Bar Mitzva as only then is he thirteen halachic years old.

In conclusion, a boy born in Adar in a regular year must wait until Adar Sheni to celebrate his Bar Mitzva. Sefardim typically observe yartzheits of those who pass away in Adar in a regular year, in Adar Sheni, while Ashkenazim typically do so in Adar Rishon.