On Which Days Do We Practice Aveilus?
1. R’ Akiva had 12,000 pairs of talmidim who all died between Pesach and Shavuos because they did not act with respect toward one another (גמ' יבמות דף ס"ב ע"ב ). This shows that the halachos of these days stem from aveilus. However, there are also sources that show these are days of din, so we do not do activities involving joy (שו"ע סי' תצ"ג ס"א ).
2. The poskim argue about which days they died on, the ramifications being on which days we practice aveilus. Multiple minhagim developed based on this, as will be explained.
3. Opinion 1. They died throughout the full 34-day period after the first day of Pesach (מדרש הובא בביאה"ל ד"ה יש). According to this, aveilus is practiced for 34 days from the start of sefira, i.e., from Day 2 of Pesach through the 34th day of the omer. After neitz on the 34th day, one may be meikel in the aveilus due to the rule of "מקצת יום ככולו" [part of a day is treated like the whole day]. This is the opinion of the Mechaber (שו"ע סי' תצ"ג ס"ב). According to this, there is no basis to be meikel on Rosh Chodesh Iyar (שו"ע ס"ג) or Lag b’Omer.
4. Opinion 2. They died during the first 33 days (ביאור הגר"א ), and aveilus is practiced during those 33 days. One may be meikel in the aveilus the morning of Lag b’Omer, but not the previous night. This is the Rama’s opinion (שם ס"ב ) [these two opinions agree that aveilus is only practiced on the days the talmidim actually died].
5. Opinion 3. They died throughout the entire period between Pesach and Shavuos, except for the 16 days on which Tachanun is not said [7 days of Pesach, including Isru Chag/Yom Tov Sheini, 6 days of Shabbos, 2 days of Rosh Chodesh Iyar, and the day of Rosh Chodesh Sivan], totaling 33 days (בשם תוס'). Accordingly, Klal Yisrael took upon themselves some aveilus for 33 days, with differing customs as to which 33 days, as follows:
6. 1. Some subtract 16 days from the beginning of sefira, i.e., from the second day of Pesach through the second day of Rosh Chodesh Iyar, thereafter practicing aveilus until Shavuos, for a total of 33 days (ב"ח, מג"א סק"ה ), despite the fact that those days are not the same 33 days R’ Akiva's talmidim died. The Rama (ס"ג ) mentions this minhag.
7. According to this, there is one day that can have the leniency of מקצת יום ככולו , and Lag b’Omer was chosen (פמ"ג ). Therefore, one may get a haircut on Lag b’Omer morning, but not from Day 34 through Shavuos (רמ"א ס"ג )—not even Rosh Chodesh Sivan (מג"א ).
8. Nevertheless, one may get a haircut on Erev Shavuos because of מקצת יום ככולו (מחצה"ש ).
9. 2. Another minhag the poskim cite is to practice aveilus from the first day of Rosh Chodesh Iyar through the morning of 3 Sivan – they are meikel on the yemei hagbala [the 3 days of preparation leading up to Shavuos] and apply מקצת יום ככולו on the morning of the first of those 3 days. They add the two days of Rosh Chodesh Iyar to keep the total at 33 (מג"א סק"ה ).
10. According to this minhag, Lag b’Omer is no different than any other day of aveilus (ט"ז סק"ב ). However, some apply מקצת יום ככולו on the morning of Lag b’Omer (ח"א הובא במ"ב ). The reason is unclear.
11. 3. Another minhag cited is to practice aveilus from after Pesach until [but not including] Rosh Chodesh Sivan, besides for two days of Rosh Chodesh Iyar and Lag b’Omer (דרך החיים הובא במ"ב סקט"ו). Some say the minhag of Eretz Yisroel is not to get haircuts or make weddings from Pesach until [but not including] Rosh Chodesh Sivan (ספר א"י להגרימ"ט סי' ח"י אות ב').
12. Opinion 4. Another minhag cited is to practice aveilus during all the days from the day after Pesach until Shavuos, besides for Rosh Chodesh Iyar and Rosh Chodesh Sivan (מג"א שם ). The Rama does not cite this, implying he does not agree with it.
13. Opinion 5. Another opinion mentioned in the poskim is that the talmidim died for 32 [not 33] days between Pesach and Shavuos. Based on this, one may be meikel starting the night of Lag b’Omer, both for weddings [below, 34] and haircuts [29]. According to this, the reason Tachanun is not said at Mincha on Erev Lag b’Omer is because it is treated like any other Erev Yom Tov (לבוש סק"ב א"ר סק"ח, שו"ע הרב ס"ה ). However, most poskim do not side with this opinion.
Establishing a Minhag
14. Within one city, there should not be some people practicing aveilus on certain days and others on different days, due to the issur of לא תתגודדו (רמ"א ס"ג ).
15. Some say that the issur of לא תתגודדו only applies in a city in which everyone has the same shul and rav. However, in today's big cities, which have many Jews from different places and many separate shuls, rabbanim, and kehilos, there is no issur (שו"ת אג"מ ח"א סי' קצ"ט ).
16. In a place without a fixed minhag, a person may keep one minhag one year and a different one the next (שו"ת חת"ס סי' קמ"ב, שו"ת מנח"י ח"ד סי' פ"ד ).
