Military time, also known as the 24-hour clock, is a system the military uses to eliminate confusion between morning and afternoon hours, since the armed forces are in operation around the clock. In ...

Many people have heard of the circadian rhythms or biological processes that follow a 24-hour cycle. Sleeping at night and being awake during the day is a well-known example of a circadian rhythm.

It’s a marvel any of us ever learns to tell time. One “day” of 24 hours divided at noon into two 12-hour chunks — why 24 and 12? And each hour consists of 60 minutes with 60 seconds to a minute — why ...