A repealer is a provision included in a statute that sets a date on which that law is repealed, or ceases to be in effect. This provision is used when the law is needed only for a certain period of time or to force the Legislature to revisit the issue in order for the statute to continue as a law.
A reverse repealer sets the revocation of the law the day before the law is to be enacted – killing the bill before it ever becomes law. A reverse repealer is most often inserted in a bill to ensure that it cannot become law without the legislation being returned to the originating chamber for additional revisions. When any change is made to a bill, both chambers must agree to those changes before the bill can go to the governor to be signed into law – including the removal of a reverse repealer.