Yahrzeit that falls on Shabbos and Yom Tov?
When the Yahrzeit falls on Shabbos [or Yom Tov], the question is raised as to when the Yahrzeit customs are to be kept. Some customs are not feasible, or not permitted, to be performed on Shabbos [and Yom Tov], and it is questionable as to when it is to be performed; on Friday before Shabbos or on Sunday after Shabbos, or perhaps they are not to be performed at all. [The same question applies regarding Yom Tov, and as to whether the Yahrzeit customs are to be performed after Yom Tov, or on Erev Yom Tov.] Practically, a dispute is recorded in Poskim in this regard. The Rebbe’s final arbitration in this matter is that all the customs that are permitted and feasible to be fulfilled on Shabbos are to be fulfilled on Shabbos, while the customs that cannot be fulfilled on Shabbos are to be fulfilled on Erev Shabbos. They may be fulfilled any time on Erev Shabbos, whether before or after midday. [The same would apply to Erev Yom Tov. This, however, is only initially, however if for whatever reason the customs were not done on Erev Shabbos, then they are to be fulfilled on Sunday.]
The customs that are initially to be fulfilled on Friday [or Erev Yom Tov] include:
- One lights the candle before sunset on Friday, or on Erev Yom Tov. [See Halacha E and F!]
- One gives Tzedaka on Friday.
- One is to visit the cemetery on Friday. [See Halacha B]
The customs that may be fulfilled on Shabbos are:
- Davening as Chazan.
- Learning Mishnayos.
Minhagei Yartzite for Tzadikim Applicable for Yud Shvat and Gimel Tamuz
From a letter of the Rebbe printed in Igros Kodesh 4:143
On the Shabbos prior to the Yarzeit, each Chassid should attempt to receive an Aliyah to the Torah.
Not enough Aliyos: If there are not enough Aliyos available, the Torah should be read [a number of times] in different rooms. No additions are to be made to the number of Aliyos at each reading.
Maftir: Maftir should be given to the most respected congregant.
- Leading the prayers:
A Chazan is to be chosen to lead the Davening on the day of the Yartzite. It is proper to choose one Chazan for Maariv, a second for Shacharis, and a third for Mincha. In this way, a greater number of Anash will have the privilege.
- Yartzite candle:
A Yartzite candle should be lit that will burn throughout the twenty-four hours. If possible, the candle should be of beeswax. [The candle should be lit immediately after sunset. Upon lighting the candle many are accustomed to say that it is being lit “Leiluiy Nishmas Peloni [i.e. name of deceased] Ben Peloni [i.e. name of father of deceased].” After the Yartzite concludes, many are accustomed not to extinguish the candle, but rather let it go out on its own.]
- Mishnayis and Kaddish after davening:
After each Davening of Maariv, Shacharis [after Tehillim] and Mincha, the Chazan should study (or at least conclude) ch. 24 of Mishnayos Keilim and ch. 7 of Mishnayos Mikvaos. He should then recite the Mishnah beginning “Rabbi Chananyah ben Akashya…,” followed silently by a few lines of Tanya and Kaddish deRabbanan.
- Study of Basi Legani on Yud Shevat [or Ata Titzaveh on Gimel Tamuz]:
After Maariv, part of the Mamar of Basi LeGani 5710 should be recited from memory. If there is no one to do this from memory, it should be studied from the text. This should also be done after Shacharis, and the Mamar should be concluded after Mincha.
- Chapter of Tanya before Shachris and after Mincha:
Before Shacharis, a chapter of Tanya should be studied. This should also be done after Minchah.
In the morning, before Shacharis, charity should be given to those institutions that are related to the Rebbe. Donations should be made on behalf of oneself and on behalf of each member of one’s family. The same should be done before Minchah.
After Shacharis and the recitation of the Mamar, each individual should read a Pidyon Nefesh. A Gartel is worn during the reading. Those who had the privilege of entering for Yechidus, or of seeing the Rebbe’s face, should picture themselves as standing before him while reading the Pidyon Nefesh. The Pidyon Nefesh should then be placed between the pages of a Maamar of his teachings, and sent, if possible, on the same day, to be read at his graveside.
Visiting the Tziyon of the Tzadik:
It is customary to visit the resting place of the Tzadik on the day of the Yartizte. Thus, those in the area are to visit the resting place of the Rebbe Rayatz on the 10th of Shevat and that of the Rebbe’s on the 3rd of Tamuz.
Checklist upon visiting a gravesite:
§ One is not to eat any food prior to visiting a grave site. Nevertheless, one is to be particular to drink before visiting.
§ One who is impure due to nocturnal emission [Keri], or any release of seed, may not visit a cemetery until he immerses in a Mikveh.
§ One who has not visited a cemetery [in thirty days] is to recite the following blessing upon seeing it:
ברוך אתה יי אלקינו מלך העולם אשר יצר אתכם בדין וזן אתכם בדין וכלכל אתכם בדין והמית אתכם בדין ויודע מספר כלכם והוא עתיד להחיותכם ולקיים אתכם בדין: ברוך אתה יי מחייה המתים: 
§ One is to distribute charity at the gravesite [prior to Davening there].
§ At the grave of a Tzaddik one is to pray to Hashem to answer his prayers in the merit of the Tzaddikim. Likewise, one may ask the Tzaddik to intervene on one’s behalf and pray to G-d for the matters which he needs. It is customary to recite a compilation of Psalm’s and prayers assembled in the booklet entitled “Maanah Lashon” upon visiting a gravesite of a Tzaddik. It is likewise customary to write a Pa”n and read it by the Ohel, tearing it upon concluding its reading and placing it near the burial site. It is best to read the Pa”n towards the area of the Tzaddik’s holy feet. If there are two Tzaddikim buried adjacent to each other then it is to be read in between the graves by the feet.
§ One may not enter a cemetery with Tzitzis that are revealed to the open. Thus one is to stick his Tzitzis into his pants prior to entering into the cemetery.
§ It is customary to light a candle by the Kever.
§ Although it is forbidden to Daven, learn Torah, or wear Tallis and Tefillin, within four Amos of a Kever, nevertheless, the custom is to permit reciting Tehillim and learn Mishnayos near the grave in his memory. See Chapter ?? Halacha ??!
§ Many have the custom of encircling the grave. The Rebbe would circle the grave one time prior to leaving.
§ Many are accustomed to place a hand on the grave upon praying [see next regarding Hishtatchus]. One is to place specifically his left hand on the grave.
§ One is to wash one’s hands three times inconsecutively after leaving the cemetery. One is to wash his hands prior to entering into a house. The custom is not to dry the hands upon leaving.
§ Some are accustomed to throw grass or earth behind their back after leaving a cemetery.
- Mishnayos in Rebbes name:
In the course of the day one should study chapters of Mishnayos that begin with the letters of his name.
One studies one chapter of Mishnayos per letter, choosing those chapters that begin with the letters of the name. For example, if the name if אברהם then one begins with a chapter that begins with an א and then continues with a chapter that begins with a ב and so on and so forth. In the event that there are two of the same letters in the name one is nevertheless to study a full chapter for each letter. However, it is not necessary to study different chapters for each repeated letter, and one may repeat the study of the same chapter. The main focus of the learning of Mishnayos should be in understanding their content and not to achieve a certain quantity of learning. This applies even if one will not be able to complete the chapters which correspond to the letters of the Niftar on the day of the Yartzite.]
When: The chapters of Mishnayos that corresponds to the name of the Niftar can be studied throughout the 24 hours of the Yartzite.
The name of the parent: When learning Mishnayos in accordance to the letters of the name of the deceased, one studies only in correspondence the name of the deceased and not the name of his parent.
Prayer after Mishnayos: It is not the custom amongst Chabad Chassidim to recite the accustomed prayer printed in Siddurim after the recital of Mishnayos.
In the course of the day one should participate in a Chassidic gathering.
- Relate to friends and family:
In the course of the day, one should set aside a time during which to tell one’s family about the saintly Rebbe, and about the spiritual tasks at which he toiled throughout all the days of his life.
- Teach others about the day:
In the course of the day, people (to whom this task is appropriate) should visit Shul’s and Batei Midrash in their cities and cite a statement from the teachings of the saintly Rebbe. They should explain how he loved every Jew. [Furthermore,] they should make known and explain the practice that he instituted of reciting Tehillim every day, studying the daily portion of Chumash with the commentary of Rashi, and, where appropriate, studying the Tanya as he divided it into daily readings throughout the year. If possible, this should all be done in the course of a farbrengen. In the course of the day, people (who are fit for the task) should visit centers of observant youth, and, those who are not yet observant, in order to explain to them the warm love that the saintly Rebbe constantly had for them. It should be explained to these people what he expected of them; they should be told of the hope and the trust that he placed in them, that they would ultimately fulfill their task of strengthening the observance of Judaism and disseminating the study of Torah with all the energy, warmth and vitality that characterize youth.
 See Piskeiy Teshuvos 568:14; Nitei Gavriel chapter 73
 Regarding the fast, some Poskim rule the fast is to take place on Sunday. [Michaber 568:9; Devar Moshe 68; Poskim in Kaf Hachaim 568:94 and so he concludes] Other Poskim rule the fast is to take place on Friday. [Kavod Chachamim, brought in Lechem Hapanim 376; Pnei Aaron 27, brought in Kaf Hachaim 568:94] Other Poskim rule that one does not fast at all in such a situation. [Rama 568:9] Other Poskim rule that although the fast is to take place on Sunday, the visitation to the Kever is to take place on Friday. [Dvar Moshe ibid, brought in Ikarei Hadaat 36:35 and Kaf Hachaim ibid] The custom of Jerusalem is to recite the prayers and Torah relevant to the Yahrzeit on Erev Shabbos. [brought in Sdei Chemed Aveilus 96, Toras Menachem 19:31]; See Nitei Gavriel 76:12
 Conclusion of Rebbe in Igros Kodesh 8:125; 14:324; Likkutei Sichos 19:132 regarding Tzedaka; Toras Menachem 19:31 [brought in Shulchan Menachem 5:323-324]
 Toras Menachem 19:31 [brought in Shulchan Menachem 5:322]
 Implication of ruling of Rebbe ibid; See Nitei Gavriel 76:14 for different customs
 Toras Menachem 19:31 [brought in Shulchan Menachem 5:322]
 Toras Menachem ibid; see also Likkutei Sichos 19:132 who discusses this matter from the aspect of a Neder and that perhaps one must wait until after Shabbos to give the charity, although concludes to give it before Shabbos in order to perform the Mitzvah as soon as possible.
 See regarding Yartzite of a parent: Birkeiy Yosef 284:1; Shaareiy Efraim 9:42; Kitzur SHU”A 78:11; Kaf Hachaim 284:6; Ketzos Hashulchan 88:1; Sefer Haminhagim p. 181 [English]; Halacha 3C!
 See Admur 282:1-3; Tzemach Tzedek 35; Ketzos Hashulchan 84:1; Sefer Haminhagim p. 61 [English]
 See Rama 376:4 regarding Yartzite of a parent; Halacha 7B!
 See Sefer Haminhagim p. 181 [English]; Sefer Hamamarim 5708 p. 146; Igros Kodesh 16:12; Toras Menachem 2 p. 125; Sefer Haminhagim p. 19 [English]; Shulchan Menachem 5:163; Halacha 7C!
 Custom of Rabbeim and some Chassidim, as explained below; See Shaareiy Teshuvah 154:20 and M”B 154:56 that it was accustomed to light a 24 hour candle in Shul on the day of the Yartzite
Custom of Rabbeim to light five 24 hour candles: The custom of the Rebbeim was to light five 24 hour candles in Shul by the Amud for the day of the Yartzite. [So was custom of Rebbe Rayatz and Rebbe Rashab, as brought in Reshimos 183:11 and so was the custom of the Rebbe, as related to me by Rabbi Leibal Groner;] This is despite the fact that Sefer Haminhagim ibid clearly writes to have it lit at the time of Davening. Rabbi Groner concluded to me that “There are many chassidim that do the same thing. Each one should do according to their feeling.”
 See regarding Yartzite of a parent: Admur 261:2; M”A 261:6; Shut Rashal 46; Nachalas Shiva 38; Kesav Sofer 75; Kitzur SHU”A 221:1; Biur Halacha 514:5 “Neir”; Mishmeres Shalom Yud 16; Kaf Hachaim 514:79; Gesher Hachaim 32:4; Nitei Gavriel 71:6; chapter 75; Sefer Haminhagim p. 180; Halacha 5!
 See Sefer Haminahgim p. 166; Nitei Gavriel 75:8
 Sefer Haminhgaim p. 180 [English]
 Torah Leshma 520
 Moed Lekol Chaiy 3; Nitei Gavriel 75:1; See Admur 610:8; Rama 610:4 regarding Yom Kippur candle
 See Sefer Haminhagim p. 36; Glosses of Rebbe to Sefer Hamamarim 1949 p. 74 and 1950 p. 6; Igros Kodesh 11:33 [published in Shulchan Menachem 5:301]
 See Minchas Yitzchak 8:53; Nitei Gavrile 90:7
 Interestingly, this custom was not directly recorded in the above-mentioned letter of the Rebbe
 The following additional Nussach is added in Maaneh Lashon:
אתה גיבור לעולם אדני, מחיה מתים אתה, רב להושיע מכלכל חיים בחסד מחיה מתים ברחמים רבים, סומך נופלים, ורופא חולים, ומתיר אסורים, ומקים אמונתו לישני עפר. מי כמוך בעל גבורות ומי דומה לך, מלך ממית ומחייה ומצמיח ישועה: ונאמן אתה להחיות מתים.
 Betzel Hachochmah 4:29; Nitei Gavriel 76:6
 See Yaavetz in Siddur Beis Yaakov Emek Habacha page 402; See Igros Kodesh Igros Kodesh 17:271 that the effects of learning Mishnayos according to the name is very different than the learning of Mishnayos in accordance to the Seder; See Halacha 10!
 Igros Kodesh 17:271, printed in Shulchan Menachem 5:313
 Nitei Gavriel 71:14
 Sefer Haminhagim p. 77; Igros Kodesh 3:128 [brought in Shulchan Menachem 5:322]
 Mishmeres Shalom Lamed 24; Igros Kodesh 17:271, printed in Shulchan Menachem 5:313; Nitei Gavriel 64:4
Other customs: Some are accustomed to also recite the chapters that correspond to the parents name. [Nitei Gavriel ibid]
 Igros Kodesh 19:214, printed in Shulchan Menachem 5:314