If child born Adar 1, and when will be 13 years old, there are 2 Adars, will bar mitzvah be adar 1 OR 2?

A boy born in Adar I of a leap year who reaches his 13th year during another leap year celebrates his bar mitzvah in Adar I — the same month in which he was born. This is the ruling of the majority of poskim (halachic decisors), since he was born in Adar I and should become bar mitzvah in the corresponding month.

Key Takeaways

A boy born in Adar I celebrates his bar mitzvah in Adar I when his 13th year falls in a leap year, according to most authorities.
A boy born in Adar II celebrates in Adar II — no dispute there, as Adar II is the "true" Adar.
The underlying debate hinges on whether Adar I is considered a "regular" month or an "added" month (ibbur).
In a non-leap year, both Adar I and Adar II boys celebrate in the single Adar.
This is a practical halachic question with differing opinions — consult a rabbi for the actual date.

Detailed Analysis

The Two Adars: Background

In a Jewish leap year (shanah me'uberet — "pregnant year"), an extra month is added: Adar I (the inserted month) and Adar II (the regular Adar). The Talmud [Megillah 6b] teaches that Adar II is the primary Adar, which is why Purim is celebrated in Adar II.

The Core Halachic Question

When a boy is born in Adar I of a leap year, and his bar mitzvah year is also a leap year, the question is:

Does he become bar mitzvah in Adar I (same name) or Adar II (the "real" Adar)?

Opinion 1: Bar Mitzvah in Adar I (Majority View)

The Rema (Rabbi Moshe Isserles) rules that one born in Adar I in a leap year celebrates in Adar I when the bar mitzvah year is also a leap year.

[Rema, Shulchan Aruch, Orach Chayim 55 and Yoreh De'ah 262:2]

His reasoning: the boy was born in a specific, named month — Adar I — and his birthday recurs in that same month.

This is also the view of the Beit Yosef and is the accepted ashkenazic practice.

Opinion 2: Bar Mitzvah in Adar II

Some authorities argue that since Adar II is the true Adar, a boy born in Adar I should become bar mitzvah in Adar II — because Adar I is merely an "inserted" month and not a full-status Adar.

This minority view holds that halachic adulthood is tied to the real Adar, not the supplementary one.

What About a Non-Leap Bar Mitzvah Year?

If the boy was born in Adar I of a leap year but his 13th year falls in a regular (non-leap) year, there is only one Adar. In that case:

All opinions agree the bar mitzvah is celebrated in that single Adar.
Some machmir (stringent) opinions suggest he should take on bar mitzvah obligations starting from the 1st of Adar to cover both possibilities.

Practical Ruling

The accepted halacha follows the majority opinion:

| Birth Month | Bar Mitzvah Year | Bar Mitzvah Month | |---|---|---| | Adar I (leap year) | Leap year | Adar I | | Adar I (leap year) | Non-leap year | Adar (only one) | | Adar II (leap year) | Leap year | Adar II | | Adar II (leap year) | Non-leap year | Adar (only one) |

A Deeper Note

The Mishnah [Eduyot 2:10] reminds us that certain judgments last twelve months — hinting at the deep significance of the monthly cycle in Jewish law. The question of which Adar is one's "true" birth month reflects a broader tension in Jewish calendar law between the natural cycle and the halachic framework imposed upon it.

For personal guidance on the specific date of your son's bar mitzvah, consult your local rabbi or posek.