A review of the evidence from diurnal physiological, seasonal environmental and prospective studies of social-behavioural functions suggest that a chronobiological theoretical model provides a comprehensive basis for the dynamics of central nervous system mechanisms, the assessment and the management of patients with fibromyalgia. The chronobiological model stresses the importance of temporal variation and the factors that influence and govern recurrent patterns of biological functions and behaviour that determine health and illness. Finally, the theory allows for an integrated study of brain, behaviour and somatic functions over time and emphasizes that such a comprehensive approach is core to any therapeutic intervention.