Chronobiology is the study of endogenous biological rhythms and the mechanisms of biological time-keeping in health and disease. The spectrum of circadian periodicities and the phase relationships between them constitute the so-called circadian time structure (CTS), which is of great relevance to medicine. Integrity of the CTS is critical for efficient biological and cognitive functioning. The practical relevance of chronobiology to meeting patient goals and optimizing outcomes of neurorehabilitation has been little explored; nonetheless, such is warranted given the findings of an increasing number of clinical studies showing detrimental interferences of poorly timed interventions and disrupted CTS.