...we also have internal clocks, governed by less understood metabolic, hormonal, and glandular processes. We listen to those inner rhythms while simultaneously responding to external cues, from daylight and moon phases to the cycle of the seasons. Still other evidence suggests a complex set of relationships between all these clocks. Body temperature rises during the daylight hours, but some people's rise faster than others, making them morning people, while those whose temperature rises more slowly over the course of the day reach their most effective state of consciousness in the early evening. Meanwhile, when our body temperature rises, we perceive of time as passing more slowly. This is because our internal clocks are counting faster, while time is actually passing at the same rate as always.