Definitions of year and a day rule
an old rule that acts or omissions that happen more than 366 days before a death cannot be found to have been the cause of that death; an old rule that a person cannot be convicted of homicide for a death that happens more than 366 days after an attack. The rule is largely historic and is no longer applied in many jurisdictions in which it was once used.
The defendant's conviction in this case is barred by the common-law year and a day rule.