Since 1901, the Nobel Prize has been awarded to scientists who have made the most important discoveries for the benefit of humanity. The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young “for their discoveries of molecular mechanisms controlling the circadian rhythm.” It may be surprising to learn that those three scientists dedicated their entire careers to research on the fruit fly, Drosophila melanogaster. However, as their studies progressed, it became increasingly clear that the mechanism of the biological clock that they discovered in Drosophila is very similar to a timekeeping mechanism present in mammals, including humans. Through interdisciplinary work between scientists performing basic research on model organisms and doctors working in medical schools, we have learned over time that daily rhythms support human health while disruption of these rhythms is associated with a range of pathological disorders such as cardiovascular problems, metabolic, neurological, and many other diseases. This short review will highlight critical milestones on the way to understanding biological clocks, focusing on the roles played by the three Nobel Prize winners.