In the 2nd century CE, a plague killed 24,000 students of one of the greatest sages and Jewish leaders of all time, Rabbi Akiba. They all died in the short span between Passover and Shavuot. During those seven weeks between the holidays of Passover and Shavuot, we commemorate that tragedy with a period of semi-mourning.
Historically, many tragedies befell our people during this period. The notorious blood libels incited anti-Semitic pogroms in the weeks following Passover.
- Hold weddings
- Listen to instrumental music
- Buy a significantly valuable garment.
- Cut our hair or shave. (Speak to your rabbi if your job requires this.)
Altogether, out of the 49 days in this period we observe only 33 days of mourning. There are, however, differing opinions when these 33 days start and end. Speak to your rabbi to determine your community/family tradition in this matter.
According to almost all opinions, however, the 33rd day of the Omer, known as Lag BaOmer, is festively celebrated, and expressions of mourning are suspended. This is the anniversary of the passing of the mystic Rabbi Shimon bar Yochai – a surviving student of Rabbi Akiba – and he specifically requested that we rejoice on the day when his soul was reunited with its Creator.
Certain communities, including Chabad, observe the Omer mourning period from Passover until three days before Shavuot (aside for Lag BaOmer), in order to be in accordance with all opinions. This custom is also in concurrence with the teachings of Kabbalah, according to which this entire period is a time of harsh judgment.
Click here for more about the Omer mourning period.

For Mark, re: harsh judgment That's Kabbalah-lingo. It means that at this time of year, the flow of life is meted out in tighter measure than at other times of year. There are cycles, patterns and rhythms to that flow, and this is one of the artifacts of that.
When you're working on yourself to rise higher and refine your character, you can override these "harsh judgments." In other words, you have to be in tune with the flow.
Who is the author of this article?
Thank you for this comment. It really spoke to my heart about rising higher and being in tune with the flow.