Based on the case of luxury hotel concierges, this paper addresses the question of how to make night work an object for the sociology of professional groups without producing an essentialist or relativist categorization of what “night time” is. To make this argument, I assemble different temporalities observed at different scales of analysis. Firstly, the micro-sociological scale of day-to-day tasks is analyzed with the tools of the sociology of work. Secondly, the scale of career paths is seen from the perspective of the sociology of employment. Finally, the broader scale of the professional group is looked at from the viewpoint of the sociology of collective mobilizations. These three scales of observation all show that the marginality of night concierges actually outlines the hidden face of the entire group. Their inclusion in the analysis, which obliges the sociologist to widen his scope of inquiry and to acquire somewhat of a night vision, is therefore vital.