The halachos of onen end once the deceased is covered with a layer of dirt. At this point, any mitzvos that the onen had not done earlier in the day, but which are still pertinent, must be done. The following outlines how this will apply in practice to various mitzvos:

Tefillos

If the time for davening has not yet passed, one must daven now. In practice, this will mean the following:

1. If one completed his aninus before the time for Kerias Shema has passed: if there is enough time to daven as usual while completing Kerias Shema on time, one davens as usual. If the time for Kerias Shema is imminent, one should first recite Kerias Shema, and then daven the full tefillah, including Shema for a second time.290
2. If one’s aninus ended close to the deadline for tefillah such that he will not have time to daven the full Shacharis before the time passes, he should shorten his Pesukei Dezimrah, reciting only Baruch She’amar, Ashrei, and Yishtabach. He then proceeds with Birchos Kerias Shema etc. as usual.291 If even this will not enable him to daven Shemoneh Esrei before the end of the time, he should daven as usual, even though that will cause him to daven Shemoneh Esrei after the time (see further). These tefillos are the minimum requirement and cannot be omitted even for the sake of davening Shemoneh Esrei before the time passes.292
3. If one first ends his aninus after the time for davening has passed, he should nevertheless daven as long as it is before chatzos (midday).
4. If the aninus ended after chatzos, the mourner may no longer daven Shacharis.
5. When the aninus ends after the time for Shacharis has passed, there is a dispute among the Acharonim as to which of the Birkos Hashachar he recites at this point. Practically, it will depend on when his aninus started. If he was an onen from alos hashachar until after the fourth hour, then he should say only the berachos of Shelo Asani Goy, Shelo Asani Aved, Shelo Asani Ishah and Birkas HaTorah. These berachos can be said the entire day.

In a case where one was not an onen at the onset of the day but became an onen before he had a chance to recite the berachos, he may recite all of the berachos after the burial.293

1. A person who was an onen throughout the entire time for tefillah does not have to daven the next tefillah twice, as is usually required for a person who missed a tefillah (tashlumin). For example, if one was an onen from alos hashachar until chatzos, he will not have to daven Minchah twice. If, however, he became an onen at some point in the morning and had been able to daven before that, he will be required to make it up at the next tefillah.294
2. If a person was an onen on motzei Shabbos295 and missed Ma’ariv, and thus did not recite Attah Chonantanu, the requirement to recite Attah Chonantanu at the next tefillah will depend: If he had already been an onen by the time motzei Shabbos arrived, he will not have to add Attah Chonantanu to the next tefillah he davens.296 However, if he first became an onen on motzei Shabbos and had been able to daven Ma’ariv beforehand, he will have to say Attah Chonantanu at the first tefillah after burial.

Tefillin

1. Although one ceases to be a onen after burial, which essentially means that he becomes re-obligated in all mitzvos at that point, tefillin is an exception to the rule. On the day of burial, a mourner does not lay tefillin at all.297

Berachos and mitzvos

1. If an onen relieved himself at some point before the burial and did not have the urge to relieve himself again by the time the burial took place, he should recite Asher Yatzar after the burial.298
2. If one ate while he was an onen and has not yet grown hungry by the time the burial was completed, he should recite Birkas Hamazon after the burial.
3. An onen who missed havdalah on motzei Shabbos should recite it after the burial, up until Tuesday evening.299 He should say it at the first possible opportunity; and he may not eat (from the burial and onward) until he recites havdalah.300 The pesukim of הִנֵּה אֵל יְשׁוּעָתִי 301 as well as the berachos of Eish and Besamim are omitted.302

It is best if others supply him with the wine for havdalah.303 This is in keeping with the general rule that the mourner’s first meal following the burial, referred to as the se’udas havra’ah, should be provided by others. Since in this case the havdalah wine is the first thing the onen will be consuming after burial, it too is regarded as part of the se’udas havra’ah.

If an onen missed havdalah on motzei Yom Tov, he recites it after the burial up until the following night.304

290 Mishnah Berurah ibid.

291 Mishnah Berurah ibid.

292 Implication of Mishnah Berurah ibid. in referring to his ruling in 52:6.

293 Mishnah Berurah ibid. If Birkas HaTorah is being said after chatzos, the aveil should recite only one pasuk from the Torah, and not the pesukim of Birkas Kohanim and Eilu Devarim (Halichos Shlomo, ibid., 2).

294 Mishnah Berurah 71:4. Note, however, that some disagree with this ruling (see Pischei Teshuvah 341:18). Therefore, it is best to stipulate that if this tefillas tashlumin is in fact not required, it should be a tefillas nedavah (Halichos Shlomo, Tefillah 18:3)

295 Halichos Shlomo, Tefillah 14:14, Devar Halachah 24; Shemiras Shabbos Kehilchasah 64, note 131.

296 Kitzur Shulchan Aruch 196:1; Sha’arei Teshuvah 294:1.

297 Mishnah Berurah 38:16.

298 Beiur Halachah 71:1, s.v. Mi.

299 Mishnah Berurah 71:10.

300 Mishnah Berurah 299:16.

301 Shemiras Shabbos Kehilchasah 64:25.

302 Shulchan Aruch 299:6.

303 Shemiras Shabbos Kehilchasah 64:25.

304 Mishnah Berurah 299:16; Hagahos Rav Ephraim Zalman Margolios, 341:24.