Ex tunc

Ex tunc is a legal term derived from Latin, and means "from the outset". It can be contrasted with ex nunc, which means "from now on". An example of usage of the term can be found in contract law, where avoidance of a contract can lead to it either being void ex nunc, i.e. from then on, or ex tunc, in which case it is treated as though it had never come into existence.