Importance
42. Aveil in the first 12 months. The birchos haftara contain tefillos for Malchus Beis Dovid, the Avoda in the Beis HaMikdash, and the Geula, as well as for the sanctification of Hashem’s name, which is similar to Kaddish. They also contain “tzidduk hadin” – “שכל דבריו אמת וצדק.” Therefore, the minhag is for aveilim within the first 12 months to get the Maftir aliya (רמ''א יו''ד סי' שע''ו ס''ד). It also benefits the niftar for his son to give the tzibbur the zechus of saying Amen after the five birchos haftara (נימוקי או''ח סק''ג).
43. 12th month. Aveilim stop saying Kaddish and davening from the amud after 11 months. Some poskim say the minhag to get Maftir also ends after 11 months (ארחות רבינו ח''ד עמ' קכ''ג).
44. However, others hold an aveil can get Maftir in the 12th month too. The purpose of the minhag is to elevate the niftar to Gan Eden, which applies all 12 months, unlike Kaddish, which is to get the niftar out of Gehinnom (משמעות הרמ''א שם, דברי סופרים פס''ג הע' א').
45. Shabbos before yahrtzeit. Over time, a minhag arose to get Maftir on the Shabbos before the yahrtzeit too, as according to the Zohar, the main time for the neshama to rise from one level to the next is on the Shabbos before the yahrtzeit (שערי אפרים ש''ט סמ''ב, חיד''א בברכת יוסף סי' רפ''ד סק''א, קיצושו''ע סי' ע''ח סי''א).
46. Minhag, not chiyuv. It should be noted that there is no chiyuv for an aveil in the first 12 months or on the Shabbos before a yahrtzeit to get Maftir; it is a good practice to the extent it is possible. Thus, he does not take precedence over other chiyuvim mentioned in the poskim. He certainly should not argue with others over this, as the purpose is to advance the neshama in Gan Eden; yielding to someone else will advance the neshama even further (כף החיים סק''ו).
