Q. I Had the first yortzait this week for my husband a’h. Can I do the Hakomas Matzeva ceremony on Pesach Sheni
A. On question 277 in regard to fasting on a yortzait day on Pesach Sheni we wrote: “Poiskim mention different traditions on Pesach Sheni in regards to reciting Tachanun, saying Slichos when it coincides with sheni chamishi vesheni, delivering eulogies and fasting.
Talmud Chulin 129b cites Megilas Taanis that includes Pesach Zeiro (the Lesser Pesach as Pesach Sheni is also known) in the list of days when eulogies and fasting is prohibited.
Binyan Shlomo (quoted in Sdei Chemed 5 p. 375) explains that although the Megilas Taanis has been in general annulled, Pesach Sheini’s restrictions may remain, as we hope that soon the Bais Hamikdash will be rebuilt and Pesach Sheni will be reinstated.
Followers of some Ashkenazi and Lithuanian traditions do recite tachanun and fast when needed on Pesach Sheni, while Chasidim and Sephardim do not (Likutey Mahariach, Eishel Avrohom 131: 20, Maharsham 6:32, Yalkut Yosef p. 649, Nitey Gavriel – Pesach 3, et al.)
Horav Shlomo Miller’s Shlit”a opinion is that an individual should follow his family’s tradition when it comes to fasting on a yortzait on Pesach Sheni.”
Horav Shlomo Miller’s Shlit’a opinion is that the same would apply to a hakomas hamatzeva ceremony.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a