This Sunday, we will all dutifully set our clocks back one hour for daylight saving time. But why is our day divided into 24 hours, each hour divided into 60 minutes, and each minute into 60 seconds?

Plan on a glorious extra hour of sleep as most of America "falls back" into standard time. But make sure to get outside for some morning sun, too — it'll help your body clock reset faster.Daylight ...

Armies started using the 24-hour method of timekeeping as standard military time because, much like police, fire, and medical departments, every branch of the armed services is in continuous operation ...