It’s Friday, and most of us probably can’t wait for the weekend to be able to sleep in. We justify shunning our alarm clocks by saying that we need to “catch up” on sleep in a futile attempt to awake refreshed on Monday morning. But often our personal and professional schedules don’t coincide with our natural circadian rhythms (our internal biological clocks) so we constantly have to retrain our bodies. Someday, however, there could be a simple drug that will reset our circadian clocks for us. In an important preliminary step toward this goal, Scripps researchers have modeled the 3-D structures of the proteins that control our master timepieces.