Lag BaOmer in the year 2025 begins at sundown on Thursday, May 15, and ends at nightfall on Friday, May 16. It is celebrated on the 33rd day of the Counting of the Omer, which corresponds to the 18th day of the Hebrew month of Iyar. This holiday commemorates the passing of Rabbi Shimon bar Yochai and marks a break in the semi-mourning period between Passover and Shavuot. Celebrations often include bonfires and outdoor festivities, especially in Israel where many visit the tomb of Rabbi Shimon bar Yochai at Mount Meron.