All in good time: temporal forms of public law decisions

Assessing when a legal entitlement begins and expires is necessary to make sense of the law. To this end, the law resorts to the following temporal slots: a present, which the law can regulate, and a past and a future that, to different extents, are usually outside of the law's scope and command. Sometimes, however, past and future issues need a present regulation, and therefore laws with a backward or forward-looking projection are enacted. Global constitutionalism is traditionally at odds with an unlimited projection of the law in time and therefore is sceptical of retroactive and 'ultractive' laws. Still, the more moderate forms of retrospective and 'ultraspective' laws can usefully tackle public law decisions, since they inherently live in a mobile flow of time that rejects a strict division between past, present, and future.