This paper takes a critical look at the role of chronobiology in society today, with particular reference to its entanglements with health and medicine and whether or not this amounts to the (bio)medicalisation of our bodily rhythms. What we have here, we show, is a complex unfolding storyline, within and beyond medicine. On the one hand, the promises and problems of these circadian, infradian and ultradian rhythms for our health and well-being are now increasingly emphasised. On the other hand, a variety of new rhythmic interventions and forms of governance are now emerging within and beyond medicine, from chronotherapies and chronopharmacology to biocompatible school and work schedules, and from chronodiets to the optimisation of all we do according to our 'chronotypes'. Conceptualising these developments, we suggest challenges us to think within and beyond medicalisation to wider processes of biomedicalisation and the biopolitics of our body clocks: a vital new strand of chronopolitics today indeed which implicates us all in sickness and in health as the very embodiment of these rhythms of life itself. The paper concludes with a call for further research on these complex unfolding relations between chronobiology, health and society in these desynchronised times of ours.