Sunset Clause

Language in a state law stating the law expires at a specified date, unless renewed by act of the state legislature. Legislation in several states raising or abolishing interest rate ceilings on credit card finance charges contains such clauses.

A provision in a sales contract that sets a date after which the agreement is no longer in effect.
Example: Since the housing market was strong and the Andersons were attracting a number of prospective buyers for their house, they insisted on a sunset clause in the contract. This provision would allow them to offer the house to another buyer should the closing be delayed for any reason.