Circadian misalignment has shown deleterious consequences on human health. Light exposure and social cues are two of the most important zeitgebers that guarantee circadian rhythms synchronization. Antarctica offers the possibility to explore and describe circadian rhythms functions during isolation and extreme photoperiod conditions. This research aimed to analyze the impact of one year of Antarctica confinement on sleep duration, naps, chronotype, and social jetlag. During five winter campaigns at Belgrano II Argentinian Antarctic Station each crew was assessed with the Munich Chronotype Questionnaire (MCTQ) throughout a year (March – May – July – Sep – Nov) (N=84). Data showed changes during winter, with less sleep duration in workdays (Month p< 0.001, post hoc July