Translation:Shulchan Aruch/Yoreh Deah/396

Seif 1: A mourner that did not perform his mourning within seven (days), whether accidentally or purposefully, fulfills it (the mourning) for all of the thirty, aside from the tearing. That if he did not tear during the time of his warmth (his raw emotion), he may tear only within seven (days), except for his father and mother, for whom he tears even after seven.

Seif 2: For what things is this said? For one that did not mourn at all during the seven (days). But if he neglected some of the days and did not perform in them mourning, such as someone that they told him a death happened to him, on the first day and he was in a different city and he did not perform mourning, and on the second day he comes to his city and performs mourning, he does not need to complete (the mourning of seven days) and he counts seven from the first day.