The Omer Period
Question
When do the Omer restrictions apply?
Answer
Shalom!
Thank you for your question.
As you correctly note, the days of the Omer have a mournful tone to them due to the death of Rabbi Akiva’s 24,000 students during this time.
As such, we do not marry during the Omer (though it is permitted to get engaged), we do not get haircuts, and men do not shave. We also do not listen to music during the Omer period.
Although the Omer period is from Pesach until Shavuos, most people only observe the mourning restrictions for 33 days. Some people observe them from Pesach until Lag B'omer and the Sephardim from 34th day of the omer. the Luach Erets Yisrael it till Rosh Chodesh Sivan and some have the minhag until the “sh'loshes yemei hagbala”. According to the Arizal one may not cut ones hair throughout the Sefirat Haomer not even on lag be'omer until the evening of the 49th day of the Omer.(although in a time of need one may cut ones hair on the 48th day of the Omer, or even on the evening of the 48th day of the omer).
Yevamos 62b; OC 493 and commentaires