1,324. After 30 Days

206:2 If the mourner received word of his relative's passing after 30 days, this is considered delayed notification and he only observes mourning for one hour. It doesn't matter if he heard during the day or at night; observing one hour of mourning is sufficient, even for a parent. However, mourning practices that one observes for a parent for the 12 months of aveilus are also observed in the case of delayed notification. In such a case, one counts the 12 months from the day of the parent's passing. If the mourner received the news after the 12 months have passed, he only mourns for one hour, including the mourning practices observed during the 12 months.

206:3 One who receives delayed notification need not observe any mourning laws; it's sufficient for him to remove his shoes. He is permitted to work, wash, anoint, engage in marital relations and study Torah. If he's not wearing shoes when he receives the news, he must perform some other action that makes it obvious that he's doing so because of mourning, such as sitting on the ground for the hour.