This year, (5767-2007), Lag B'Omer, the thirty-third day of the Omer, the 18th day of Iyar, is on Sunday 6th May 2007. The festival gets it's name from it's description as Lag B'Omer as 'Lag' means the number 33 in Hebrew.
The Omer period lasts for 49 days from Pesach to Shavout and through the years, the period has become identified with sad memories for Jews. Massacres occurred during the period of the Romans and later still during the Crusades, in the days of the Roman Emperor Hadrian, the Jews - led by Bar Kochba - attemped to drive out the foreign oppressors from Judea. The revolt was unsuccessful and during the fighting thousands of Jews lost their lives. According to the Talmud, (Tractate Yevamot 62b), 24,000 students of Rabbi Akiva died in one short period, because "they did not show proper respect to one another!" as a result of a mysterious God-sent plague that raged during the days of the Omer counting. However on one day only, Lag B'Omer - Rabbi Akiva's pupils did not die. It was made into a festival in the middle of days of mourning that precede and follow it.
Lag B'Omer is celebrated with a day of outings and spending time outdoors. Weddings often take place as they are not permitted during the Omer.