Sleep duration has been constantly decreasing over the past 50years. Short sleep duration, sleep quality and, recently, long sleep duration have all been linked to poor health outcomes, increasing the risk of developing metabolic diseases and cardiovascular events. Beyond the duration of sleep, the timing of sleep may also have consequences. Having a tendency to go early to bed (early chronotype) compared with the habit of going to bed later (late chronotype) can interfere considerably with social schedules (school, work). Eventually, a misalignment arises in sleep timing between work days and free days that has been described as ‘social jet lag’. The present review looks at how different sleep habits can interfere with diabetes, excluding sleep breathing disorders, and successively looks at the effects of sleep duration, chronotype and social jet lag on the risk of developing diabetes as well as on the metabolic control of both type 1 and type 2 diabetes. Finally, this review addresses the current state of knowledge of physiological mechanisms that could be linking sleep habits and metabolic health.