Judicial notice is a rule in the law of evidence that allows a fact to be introduced into evidence if the truth of that fact is so notorious or well known, or so authoritatively attested, that it cannot reasonably be doubted. This is done upon the request of the party seeking to rely on the fact at issue. Facts and materials admitted under judicial notice are accepted without being formally introduced by a witness or other rule of evidence, and they are even admitted if one party wishes to lead evidence to the contrary. Judicial notice is a rule in the law of evidence that allows a fact to be introduced into evidence if the truth of that fact is so notorious or well known, or so authoritatively attested, that it cannot reasonably be doubted. This is done upon the request of the party seeking to rely on the fact at issue. Facts and materials admitted under judicial notice are accepted without being formally introduced by a witness or other rule of evidence, and they are even admitted if one party wishes to lead evidence to the contrary. Judicial notice is frequently used for the simplest, most obvious common sense facts, such as which day of the week corresponded to a particular calendar date or the approximate time at sunset. However, it could even be used within one state to notice a law of another state—such as one which provides average baselines for motor vehicle stopping distances. In the United States, Article II of the Federal Rules of Evidence ('FRE') addresses judicial notice in federal courts, and this article is widely copied by U.S. States. Article II of the FRE consists of a single rule, Rule 201. FRE 201 covers judicial notice of adjudicative facts, which are those concerning the parties to a proceeding, but not of legislative facts, which are general.