Kaddish D'Rabbanan on Yartzeit

Question

On a yartzeit, close family members recite kaddish. Some minyanim have an opportunity to say kaddish d'rabbanan after (sometimes short) Torah study between mincha and maariv. Should the mourner join this kaddish d'rabbanan at the beginning of the yartzeit day (before the maariv where kaddish yatom is said)? What about at the end of the day (after the mincha where kaddish yatom is said)? Is the decision based on whether it is before or after shkia at the time or some other criteria?

This question pertains only to minyanim where the custom is for all mourners to say kaddish d'rabbanan together, not where only one person (typically the chazan or someone who has just finished conducting the Torah study) says it regardless of mourning status. For purposes of this question, please assume the mourner in question has neither of these roles.

Answer 1

You asked: What about at the end of the day?

The Kitzur Shulchan Aruch in סימן כו - דיני קדיש יתום says:

סעיף כ"א: מִי שֶׁהָיָה לוֹ יָאהרְצַיְיט, וְלֹא [הָיָה] יָכוֹל לוֹמַר קַדִּישׁ, כְּגוֹן, שֶׁהָיָה בַּדֶּרֶךְ, אוֹ שֶׁלֹּא הִגִּיעַ לוֹ קַדִּישׁ, יָכוֹל לוֹמַר קַדִּישׁ בִּתְפִלַּת עַרְבִית שֶׁלְּאַחַר הַיָּאהרְצַיְיט. ‏

So it's documented that the Kadish during Maariv after the Yahrzeit counts - in emergency - as being part of the Yahrzeit.

Answer 2

When I started saying kaddish for my mother many years ago, I asked the same question of my rabbi. His response was it was up to me. I established the custom for myself to say the kaddish d'rabbanan following the brief Torah study between mincha and maariv both on the eve of the yahrzeit (when the yahrzeit started with maariv) and at the conclusion of the yahrzeit (when the yahrzeit ended with mincha.

My rabbi was Rabbi Joseph Radinsky (now retired), United Orthodox Synagogues of Houston.