Ask most American Jews “What’s Lag B’Omer?” and you’ll likely get some befuddled looks. But this festival – which begins on the evening of May 2, and concludes on May 3 at sundown — has been observed by Jews of all backgrounds for millennia.

Lag B’Omer is a festive minor holiday that occurs on the 33rd day of the Omer, which is the 49-day period between the second day of Passover and Shavuot. During the semi-mourning Omer period, Jews are forbidden from holding Jewish weddings or other celebratory events as well as listening to music or getting haircuts – except on Lag B’Omer, which is observed on the 18th day of the Hebrew month of Iyar.

The roots of Lag B’Omer – and the Omer itself — are nebulous. “To this day, no Jewish scholar can state with certainty exactly what Lag B’Omer celebrates,” writes Rabbi Joseph Telushkin in his seminal work “Jewish Literacy: The Most Important Things to Know About the Jewish Religion, Its People and Its History” (William Morrow and Co.).

The most oft-cited explanation comes from the Talmud, which contends that a plague killed thousands of Rabbi Akiva‘s students during this season due to their lack of respect and civility toward each other. According to tradition, the plague ceased on Lag B’Omer, which stands for the Hebrew letters lamed and gimel, combining for the numerical value of 33.

Some commentators also contend that Lag B’Omer was the day on which the Bar-Kochba Rebellion may have achieved a crucial victory against Rome in the second century of the Common Era.

As a result, Lag B’Omer became recognized as a joyous communal day, interrupting the solemnity of the Omer period for a 24-hour respite.

On Lag B’Omer, Jews are permitted to have weddings, parties, parades, bonfires, picnics and other outside outings, as well as get haircuts and listen to music. Children traditionally go out to fields with bows and arrows, possibly as a reminder of the fierce battles fought by Rabbi Akiva’s students in the Bar-Kochba Rebellion.

In Israel, tens of thousands of Jewish pilgrims visit the final resting place of the great Mishnaic sage and mystic Rabbi Shimon bar Yochai on Lag B’Omer in the northern village of Meron. Lag B’Omer is the anniversary of Rabbi bar Yochai’s death in the second century.

A disciple of Rabbi Akiva, Rabbi bar Yochai was reportedly the first spiritual leader to publicly teach the mystical dimension of the Torah known as Kabbalah, and is believed to be the author of the classic text of Jewish mysticism known as the Zohar (Book of Splendor). Tradition holds that on the day of his passing, Rabbi bar Yochai instructed his disciples to mark the date as “the day of my joy.”

Lag B’Omer bonfire events will be held at synagogues throughout the local Jewish community May 2 (at Congregation Tiferes Yisroel, 6201 Park Heights Ave., and Congregation Shomrei Emunah, 6221 Greenspring Ave.), May 3 (The Shul at the Lubavitch Center, 6701 Old Pimlico Road) and on the evening of May 4 (Congregation Beit Tikvah, 5802 Roland Ave.)

The information for this article was culled from various sources and websites.

Also see: Officials in Israel say heat wave makes it too dangerous to hold holiday bonfires