The paper focuses on temporal aspects of informal caring for older people. Limitations of large-scale surveys in capturing such data are noted and time-use methodology, despite its own limitations, is proposed as a promising alternative. Adopting a critical perspective on time that includes carers' own conceptualisations, we report the findings of a qualitative study of carers' time use. Sixty-two interviews with carers, male/female, co-resident/not co-resident, employed/not employed, and located across Great Britain were conducted. Analysis considered people's own diverse and ambiguous views of their care activities. Carers' accounts of their time revealed non-linear experiences and a sense of being permanently on call. Interviewees often travelled distances to engage in support activities with or for older people. Changes over time were pervasive, increasing or reducing care requirements. Unanticipated events could precipitate radical changes in time use. Managing time, exercising temporal agency, was particularly apparent in accounts of care, employment, other family responsibilities and choices about friendship. Measurement of carers' time use which draws on the conceptual foundation of carers' own perspectives on time may provide more effective quantitative understanding of the temporal aspects of caring. It should not pre-define time, must grasp a variety of tasks, take account of intermittent activity, incorporate the 24–7 experience of many carers and demonstrate how caring time interacts with other time.