אורח חיים ע״אOrach Chayim 71

Se’if 1א׳

מִי שֶׁמֵּת לוֹ מֵת שֶׁהוּא חַיָּב לְהִתְאַבֵּל עָלָיו, אֲפִלּוּ אֵינוֹ מֻטָּל עָלָיו לְקָבְרוֹ, פָּטוּר מִקְּרִיאַת שְׁמַע וּמִתְּפִלָּה. וַאֲפִלּוּ אִם רוֹצֶה לְהַחְמִיר עַל עַצְמוֹ וְלִקְרוֹת, אֵינוֹ רַשַּׁאי. וְאִם יֵשׁ לוֹ מִי שֶׁיִּשְׁתַּדֵּל בִּשְׁבִילוֹ בְּצָרְכֵי קְבוּרָה, וְרָצָה לְהַחְמִיר עַל עַצְמוֹ וְלִקְרוֹת, אֵין מוֹחִין בְּיָדוֹ וְעַיֵּן בְּיוֹרֵה דֵּעָה סי' שמ"א.

A Mourner and Those Occupied With a Deceased Person are Exempt from the Recitation of the Sh'ma - containing 7 S'ifim One who's relative died, for which he is required to mourn for them: even if it is not his responsibility to bury them, he is exempt from the recitation of the Sh'ma and from Tefilla [i.e. the Amidah]. And even if he wants to be strict with himself and to recite [it], he is not permitted [to do so]. But if one has someone who will take care of the needs of the burial for him, and he wants to be strict with himself to recite it, we do not protest against doing so [and see Yoreh Deah 341].

Se’if 2ב׳

בַּמֶּה דְּבָרִים אֲמוּרִים, בְּחֹל. אֲבָל בְּשַׁבָּת, חַיָּב כָּל הַיּוֹם עַד הָעֶרֶב אִם מַחְשִׁיךְ עַל הַתְּחוּם לְהִתְעַסֵק בְּצָרְכֵי קְבוּרָה. אֲבָל אִם אֵינוֹ מַחְשִׁיךְ עַל הַתְּחוּם, חַיָּב גַּם לְעֵת עֶרֶב, וְיוֹם טוֹב שֵׁנִי דִּינוֹ כְּחֹל וְעַיֵּן סי' תקמ"ח סָעִיף ה'. וְיוֹם טוֹב רִאשׁוֹן, אִם רוֹצֶה לְקָבְרוֹ בּוֹ בַּיּוֹם עַל יְדֵי עַכּוּ"ם, דִּינוֹ כְּחֹל. וְאִם אֵינוֹ רוֹצֶה לְקָבְרוֹ בּוֹ בַּיּוֹם, דִּינוֹ כְּשַׁבָּת.

When does this apply? Regarding weekdays, but on Shabbat, one is obligated all day until evening if they are waiting until night at the [edge of the Shabbat] boundary to busy themselves with the needs of the burial [immediately after Shabbat]. But if one is not waiting until night at the boundary, they are obligated also at evening time. And [regarding] the second day of Yom Tov, its rule is like an ordinary day (and see Siman 548:5). And on the first day of Yom Tov, if one wants to bury [the dead] during that day, by means of non-Jews, then its rule is like a weekday, and if one does not want to bury him on that day, its rule is like Shabbat.

Se’if 3ג׳

הַמְשַׁמֵּר אֶת הַמֵּת, אֲפִלּוּ אֵינוֹ מֵתוֹ, פָּטוּר.

The one who watches the deceased, even if it is not one's own deceased is exempt.