Translation:Shulchan Aruch/Yoreh Deah/402
Seif 1: One who received word that a relative died, if the message arrives within 30 days (of the death), even on the 30th day itself, this is considered a shemuah kerovah and he is obligated to observe the 7 days of mourning [shiva] from the day that the message arrived, and to tear kriah, and to count 30 days (Rema: From the day he received the message) with regard to getting a haircut and other [such] things. The general idea is that the day one receives the shemuah kerovah is like the day of burial. But if he hears [the message] from the 30th day and onwards, it is not necessary to observe [the laws of mourning] except for an hour [i.e. a very short amount of time], regardless of whether he heard this during the daytime or at nighttime, because if he heard at nighttime and partially observed mourning practices at night for an hour, this counts [as observing], and this is even if he heard about [the death of] his father or mother. This refers to the law of the seven days [of shiva], but with regard to the law of the 30 days, he should observe for his father or mother not to get a haircut until his friends chastise him, and [he should not] iron [his clothing] until he reaches the next festival and they chastise him, and [the rule is similar] with regard to greeting and going to a party. And he counts from the day of death and not from the day [that he received] the message. Therefore, if he received the message about his father or mother after 12 months, he only needs to observe a single day, even for the decrees of 30 days.
Seif 2: One who receives a shemuah rehoka does not need to observe all of the rites of mourning, rather, it is sufficient for him to take off his shoes, and he does not need to wrap [his head] nor to overturn his bed, and he is permitted to perform work, to bathe, to anoint, and to have sexual relations, and to study Torah. And if he does not have shoes on his feet, he needs to over turn his bed, or wrap his head, because he needs to perform an action that is recognized that he is doing it because of mourning. And if he was busy studying Torah or working, or he was bathing and anointing, and he received the message, it is enough that he stops for an hour for mourning, and then he returns to what he was doing, but if he was wearing tefillin, he does not need to remove them. Nevertheless, he has not fulfilled his mourning [obligation] through this break, and he needs to perform an action that it is recognizable that he is doing it because of mourning, such as taking off his shoes or overturning his bed and wrapping [his head], however a single one of these is sufficient.