A period of time running from any date until the same date in the following year, e.g. from January 1 to January 1 of the following year. At common law, the statute of limitations for filing certain claims and prosecuting certain crimes. The term arose because a year from January 1 would traditionally run through December 31, not January 1. Also called "year and day."
See, e.g. Rogers v. Tennessee, 532 U.S. 451 (2001).