The success of legal time in migration law is exemplified by the multitude of possibilities to differentiate, categorize, and calculate human life by means of time. This is based on an intricate play between two complementing and contradicting forms of time: human time and clock time. The success of clock time in law can be related to its objective character, which allows for quantification and calculation. It is this quantification that provides a clarity and logic to processes that are otherwise rather intangible. It is the transformation from an individual process of human time into quantifiable, calculable chunks of clock time that enables the simple, general application in law. An extra value of this generality is its visibility, it is easy to demonstrate that a certain policy has changed based on clock time. However, legal time cannot be equated with clock time, the reference to time in law is always the time of someone, and therefore it is characterized by temporality. The virtues of legal time can be seen at work in several temporal differentiations in migration law: differentiation based on temporality, deadlines, qualification of time, and procedural differentiation.

The jus temporis that is argued for in this chapter aims to explicate the value of human time that is to be found in the finite, irreversible, and unstoppable character of human time. To make the value of human time explicit, "rootedness" and "integration" are conceptually distinguished. The latter signifying qualified time, the former mere lapse of human time. Rootedness simply signifies the entanglement of presence on a territory with the lapse of finite and irreversible human time. This conception of rootedness is at the heart of jus temporis and its implications are not limited to questions of citizenship acquisition. It is argued that the value of rootedness equally applies to waiting time in procedures, endless forms of temporariness, and unlawful residence. Concretely, it is argued that this jus temporis implies two elements. The first is a certain openness to the future, the possibility that a certain situation will not last forever. The second element is that there should be end-terms at work in law: procedures may not last forever, temporariness may not continue eternally, and there should be a moment when long-term unlawful residences can become lawful.