Lag BaOmer, 18 Iyar

Lag BaOmer falls on the eighteenth of Iyar, the thirty third day of the Counting of the Omer, the forty nine day count the Hebrew calendar runs between Passover and Shavuot, and the date this rule records marks the one day within that count when the customary restrictions on weddings, haircuts and music kept during the rest of the Omer period are lifted. The Talmudic explanation for why the Omer is kept as a semi mourning period at all traces to a plague said to have killed a great number of the students of the second century sage Rabbi Akiva, a plague tradition holds ceased on this specific day, thirty three days into the count, giving Lag BaOmer its character as a day of relief within an otherwise restrained season.

The date carries a second association layered onto the first, as the traditional yahrzeit, the anniversary of death, of Rabbi Shimon bar Yochai, a disciple of Akiva credited in later tradition with authorship of the Zohar, the foundational text of Kabbalah. That association gives the day particular significance in Kabbalistic and Hasidic circles, most visibly at Mount Meron in northern Israel, where enormous crowds gather annually for bonfires, music and celebration at the traditional site of Shimon bar Yochai's tomb, a scale of observance for what began as a minor calendar exception that has grown considerably beyond its original, narrower explanation.