A more thorough explanation:

Definition: The term "year and day" refers to a legal rule that was used in the past to determine whether a death was caused by someone's actions. Under this rule, if a person died more than a year and a day after being injured, it was presumed that the injury was not the cause of death. This rule is no longer used in most jurisdictions.

Illustrative caselaw: One example of a case that involved the year and day rule is Rogers v. Tennessee, 532 U.S. 451 (2001). In this case, the defendant was charged with murder after the victim died 14 months after being shot. The defendant argued that the year and day rule should apply and that he could not be held responsible for the victim's death. However, the Supreme Court of the United States rejected this argument and held that the rule did not apply in Tennessee.

Example: Imagine that a person is injured in a car accident and dies 13 months later from complications related to the injury. Under the year and day rule, it would be presumed that the injury was the cause of death and that the person who caused the accident could be held responsible. However, in most jurisdictions today, this rule no longer applies and the cause of death would be determined based on medical evidence and other factors.