Leviticus 23:15-16: “And you shall count for yourselves from the day after the Sabbath, from the day that you brought the sheaf of the wave offering: seven Sabbaths shall be completed. Count fifty days to the day after the seventh Sabbath; then you shall offer a new grain offering to the LORD.”
On the 14th of May 2017, Jews all over the world will celebrate ‘Lag B’Omer’. ‘Lag B’Omer’ is Hebrew shorthand for the 33rd day of the ‘Omer’. ‘Lag’, or L"G is the Hebrew numerals for 33. It falls on the 33rd day of the counting of the ‘Omer’ (the amount of days as counted from the second day of ‘Pesach (Passover) until the holiday of ‘Shavuot’.) This corresponds to the 18th day of the Hebrew month of ‘Iyar’.