My son is the gabbai of our shul and he followed the minhag of our shul by announcing that he would be doing Kail Malei for each person who needed it at Mincha of Shabbos Mevorchim. Everyone who needed it came up at Mincha to have it done. Our shul has three mincha minyonim on Shabbos (after Daylight Savings Time starts), 2 P.M., 5:30 P.M. and a later mincha giving enough time to go home for shalosh seudos.
Most people do not wait until Monday or Thursday Shacharis because of practical problems in going to work afterwards.
In any case, the Kail Malei is supposed to be done before the actual Yahrtzeit (as stated in the Minhagim for the Gabbai sefer that we use.)
Yahrzeit Observances in Shul
Malei Rachamim Prayer:
If the Yahrzeit falls on Shabbos, the one observing a yahrzeit recites the “Malei Rachamim” prayer found in Artscroll p.454 after the
Torah and Haftorah service on Shabbos.
If the Yahrzeit falls on Sunday, Tuesday, Wednesday, or Friday, the one observing a yahrzeit recites the “Malei Rachamim” prayer found
in Artscroll p.454 after the Torah and Haftorah service on the Shabbat
prior to the yahrzeit.
If the Yahrzeit falls on a Monday or Thursday, some have the custom to recite the ”Malei Rachamim” prayer on the day of the
Yahrzeit instead of the Shabbos prior.
Others have the custom to
recite the ”Malei Rachamim” prayer on the Shabbat prior to the