Some Laws of Mourning for a Grandfather Who Passed Away on Friday and Was Buried on Saturday Night

When his father's father passed away on Friday and was not buried until Saturday night, should some mourning practices be observed in the week following the burial?

Since some mourning practices are observed from the burial until the following Shabbat, and since his father's father was buried on Saturday night, some mourning practices should be observed until the Shabbat after the burial. However, it is permitted on the Friday before the second Shabbat to bathe in hot water in honor of Shabbat, even if he does not usually do so every Friday. If his relative is not present at the burial but is in a distant place where mourning begins on Friday, it is clear that they follow the time when mourning began and observe until the first Shabbat.

In the Torah and Rema, Siman 374, Sif 6, it is explained that this mourning is observed from the burial until the following Shabbat. And since the burial was on Saturday night, it is observed until the following Shabbat. However, the Ktav Sofer writes that if the seventh day falls on Shabbat, it is permitted on Friday to bathe in hot water out of respect for Shabbat, even if he does not usually do so every Friday.