Ex nunc is a Latin term that means “from now” or “from now on.” It is frequently found in legal terminology, where it can be used to describe the jurisdiction of a ruling or contract. It is also used in contrast with ex tunc, another Latin phrase that translates as “from the outset” or “from the beginning.” An ex nunc ruling can affect things only from the moment of its existence onward.
Contrasting ex nunc and ex tunc is a little like understanding the difference between a divorce and an annulment. While a divorce means that a marriage is ended from the point of the final decree onward, an annulment stretches back into the past to declare that the union never legally existed. Similarly, an future-altering decision or situation deals with events moving forward, such as the termination of a legal contract. An ex tunc ruling, however, might declare that a contract was invalid from its inception.
There are several instances when this concept is important to legal procedure. Contract law is one such situation, in which clauses may specify actions, agreements, or conditions for the future of the contract, but do not refer to prior agreements. Laws or legal systems that permit amendments are also usually subject to measures that take effect ex nunc.
Knowing when this type of clause or ruling comes into effect can have a profound impact on criminal and civil law proceedings. If in 2002, a nation outlawed square-dancing ex nunc, a person could not be prosecuted or ticketed for square-dancing prior to the law taking effect. On the other hand, if in 2004 the nation added an exemption that allowed high schools to have square-dancing fundraisers ex nunc, fundraisers held before the exemption took effect could potentially be in danger of prosecution.
The institution of Prohibition in America in the early 20th century is an example of ex nunc laws. The 18th amendment of the US Constitution banned the sale and production of alcohol “after one year from the ratification of this article.” This ruling dictated future behavior, making it a perfect example of a law that took effect “from now on.” When the 21st amendment repealed Prohibition, it also took effect ex nunc. Repealing a law through these types of rulings does not mean that the law was illegal, or that those prosecuted under a former law were treated unlawfully. As opposed to the annulment of a law, a repeal merely says that the law is now changed.
