The 2015 Chronobiology GRC will present cutting-edge research on nearly all aspects of chronobiology with a special focus on circadian biology: molecular, cellular, systems, neural, physiological and behavioral. The Conference will feature a wide range of topics: e.g., the molecular mechanisms of circadian and non-circadian clocks; the control of physiological functions such as cell cycle, immune system, metabolism and aging by clocks, as well as the implications for health and disease; seasonal and ultradian cycles; entrainment mechanisms and control of sleep timing; the neurobiology of circadian clocks; as well as conceptual aspects of clocks and oscillators. The Conference will feature a wide range of organisms, from prokaryotes and lower eukaryotes to plants, animals and humans. Invited speakers represent a variety of scientific disciplines, including biochemistry, molecular genetics, immunology, cell biology, developmental biology, imaging, modeling, sleep research, neuroscience, behavior and human biology. The Conference will bring together a collection of established and upcoming investigators who are at the forefront of their field, and will provide opportunities for junior scientists and graduate students to present their work in poster format and exchange ideas with leaders in the field. Some poster presenters will be selected for short talks. The collegial atmosphere of this Conference, with programmed discussion sessions as well as opportunities for informal gatherings in the afternoons and evenings, provides an avenue for scientists from different disciplines to brainstorm, and promotes cross-disciplinary collaborations in the various research areas represented. The 2015 Chronobiology GRC will offer a companion Gordon Research Seminar (GRS), organized along the same themes as the Conference. The GRS will be held immediately preceding the Chronobiology GRC at the same venue. More junior scientists, such as students, postdocs and newly established investigators, are encouraged to attend. They may seek more background in the field and/or the opportunity to present their work to an audience of peers. Some of these presentations will be chosen for short talks at the GRC to follow.