This article explores how scientists make and feel time in the context of the chronobiological laboratory. Like other scholars who have tracked the temporal regimes of scientific knowledge making, I am interested in the kinds of times produced in and around experiments performed by the scientists who study circadian rhythms. During gruelling ‘time point’ experiments, chronobiologists attempt to mould their own rhythmic, biological bodies to a scientific temporality that emphasises exactness and regularity to facilitate almost continuous data collection. Within this complex ‘timescape’, scientists tinker with time itself in order to navigate the multiple temporalities produced by their research. They deploy a scientific time convention known as ‘Z-Time’ or ‘zeitgeber time’ as a method of ‘time work’ that allows them to customise the temporal experience of their working lives and their experimental subjects, lab mice. I argue that a case study of the chronobiology lab questions the extent to which time can be ‘worked’ in the context of biological research. I explore what the tension between scientific and embodied times can tell us about the role of temporality in making ‘good science’ and the ‘emotional culture’ that time point experiments foster among chronobiologists.