Lag BaOmer is a Jewish holiday that falls on the 33rd day of the Omer, the period of time between the Jewish holidays of Passover and Shavuot. It is traditionally celebrated on the 18th day of the Hebrew month of Iyar, which usually falls in May or June in the Gregorian calendar.

Lag BaOmer has several different historical and cultural associations, but the most common explanation for its celebration is as a break in the mourning period of the Omer. According to Jewish tradition, the Omer is a period of semi-mourning that commemorates a time of great tragedy in Jewish history. During this period, weddings, parties, and other joyous occasions are typically avoided, and people may observe various forms of mourning, such as refraining from shaving or cutting their hair.

However, on Lag BaOmer, some of these mourning practices are lifted, and it is considered a time of celebration and joy. There are many customs associated with Lag BaOmer, including lighting bonfires, playing with bows and arrows, and visiting the gravesite of the famous Jewish sage and mystic Rabbi Shimon bar Yochai, who is believed to have died on this day. It is also a popular time for weddings, as the restrictions on celebration during the Omer period are lifted on this day.