The Chronobiology in Medicine is a quarterly, open access, peer-reviewed online journal that publishes research articles dealing with the circadian rhythms in various medical fields and clinical sleep medicine. The Chronobiology in Medicine covers various biological rhythm studies, including sleep and wakefulness, in various medical areas, basic sciences and social sciences. Topics on the clinical sleep disorders such as sleep disordered breathing and insomnia influencing on the circadian rhythm disturbances will be considered for publication. The Journal publishes Editorial, Review Article, Original Article, Brief Report, Perspective, and Correspondences. The Chronobiology in Medicine is the official journal of the Korean Academy of Sleep Medicine (KASMED).