The evolution of the population living in establishments for the elderly, that is to say the increasing number of people suffering from cognitive disorders, challenges the traditional division of day and night. Night-time is henceforth part of gerontology action plans (Plan Solidarité Grand Age, Plan Alzheimer...). In answer to those inducements, innovative processes are set by professionals in order to meet the needs of people confusing day with night: Is the bedroom the only place one can sleep in? Does one have to eat at meal times only? And practice activities only during the day? Such questions force the rearrangement of the concept of space-time, and force to rethink day and night rhythms. The aim of innovative night-time practices is to improve the respect of self choices and habits by producing stimulating and inclusive new models for social institutions that affect identity markers and the feeling of control on one’s environment.