The 2009 Gordon Conference on Chronobiology will present cutting-edge research on the molecular, cellular and systems aspects of circadian biology. The Conference will feature a wide range of topics, such as the dynamics of transcription and cell cycles, molecular mechanisms of clocks, genetics of human clocks, metabolism and clocks, novel functions for clock genes, model organism clocks, entrainment mechanisms, and the neurobiology of the suprachiasmatic nucleus. Invited speakers represent a variety of scientific disciplines, including biochemistry, molecular genetics, genetics, genomics, structural biology, cell biology, imaging, modeling, sleep medicine, neuroscience, behavior and human biology. The Conference will bring together a collection of 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.