The date of the shiloshim for halachos of Avalos depend on the day the shiva started. There is a minhag to learn mishnayos for a niftar and finish at or before the shiloshim. I believe this is a zechus for the niftar , and not part of aveilos. (many people who are not related to the niftar participate in the learning) Does the shiloshim for learning mishnayos start when the person is niftar or does it depend on when the shiva starts? If it depends on the first day of shiva, and different members of the family started Shiva on different day, when is the shloshim for a non-relative learning mishnayos? thank you

ב"ה Shalom The customs of the Azcara, the memorial ceremony, are conducted on the shloshim, the 30th day from the burial as the Neshama is judged especially within the 30 days from burial. See ( ילקוט יוסף אבלות ל"ו: ב, רבבות אפרים חלק ח סי' תכ"ב ) So they can finish the Mishnayot according to the burial. Besorot Tovot All the best