Researchers studying the molecular mechanisms of our biological clocks have made a critical breakthrough, identifying a key interaction that controls the timing of our body's internal clock. This discovery provides significant insights into Familial Advanced Sleep Phase Syndrome (FASP), a condition caused by a genetic mutation that accelerates the body's internal clock, resulting in a 20-hour cycle instead of a 24-hour one. The mutation disrupts the interaction between a core clock protein, Period, and an enzyme, resulting in an imbalance leading to a shortened clock cycle.