Visiting the grave of a relative at the conclusion of 11 months from the passing [i.e. 21st of Menachem Av for those murdered on Oct 7th HYD]:

Question:

My son who served in an elite unit in the IDF was killed during battle on October 7 [22^nd of Tishreiy] HYD. I was given three different dates by the chaplain of his division for visiting the cemetery with a ceremony. The first being at the conclusion of the 11 months from the passing, the second being at the conclusion of the 12 months of mourning, and the third being after Simchas Torah. He said technically if I want I can choose all three. What dates should I follow?

Answer:

You should visit the grave both at the end of the 12 months [i.e. 21st Elul], and in proximity to the day of the passing, which is after Simchas Torah, and you can do a ceremony on both dates. Ashkenazim do not visit the grave or make a ceremony at the conclusion of the 11 months, although this is practiced by some Sephardim, although even according to them, the main time for the visitation and ceremony is at the conclusion of the 12 months, or Yartzite. Notwithstanding the above, some are accustomed to make Lechayim in Shul on the day they finish reciting Kaddish at the conclusion of the 11 months.

See regarding visiting by the end of 12th month: Michaber 344:20 based on Tur and Rav Haiy Gaon regarding a Chacham, Aluf, Vegaon, and some are accustomed to do so for all deceased relatives; Nitei Gavriel 65:22; See also Michaber O.C. 547:8 and Y.D. 347:3 that the custom is to recite Hespedim and say Hazkara at the end of the 12th month; As the soul of the deceased is elevated on the 12th month to Heaven and does not come back down again.  Nitei Gavriel 76:9 See regarding visiting by the Yartzite: Rashi Yevamos 122a regarding Yahrzeit of Tzaddik; Kav Hayashar 71 “The custom has spread to visit the Kever of one’s parents on the day of their Yartzite”; Tiferes Yisrael Eidiyus 2 “It is proper on the day of the Yartzite to visit the Kever, as doing so has a great effect on the soul on this day”; Kesav Sofer Y.D. 179 “So is the custom to Daven for the deceased on the day of the Yartzite, and a son honors his father””; Misgeres Hashulchan 376; Darkei Hachaim 34:20; Mishmeres Shalom Yud 16; Nitei Gavriel 71:18; Chapter 76:1 footnote 1 in length See regarding visiting the grave during the first year, prior to 12^th month: See Tur 344 in name of Kol Bo “And one visits him on the day of the Shloshim, and no longer”; Maharam Brisk 2:29; Mishmeres Shalom Hei 26; Gesher Hachaim 29:2; Kinyan Torah 119; See Igros Kodesh 9:301 [printed in Shulchan Menachem 5:328] “Regarding visiting your fathers Kever during the 12 months, it is dependent on the Minhag of the community, as there are places who are careful in this during the first 12 months. However, if there is no set custom and especially during the months of Elul and Tishreiy, then it is not a big deal for him to go.” See Nitei Gavriel 81:4-7 for all the opinions on this matter!; See Nitei Gavriel 81 footnote 3 and 10 based on Zohar that during the first year the soul knows of his own suffering and cannot be bothered with suffering of others; See regarding making a ceremony and meal on the day they finish reciting Kaddish at end of 11 months [however, no mention is made regarding visiting grave then]: Rav Poalim 3:10-32; Ben Ish Chaiy Vayechi 14; Nesivos Hamaarav 136-137;  Nitei Gavriel 52:4; Yalkut Yosef Aveilus 40:3