Most people’s clocks run on about the same schedule. But some are a little outside the typical range. Larks rise early, alert and raring to go. Owls? You have to drag them out of bed, but once evening rolls around, they’re on it. Scientists think larks may have slightly faster clocks, and owls slower ones. Fast, slow, or in between are all fine. The key is to work with your clock, not against it.