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?

How I spend my hours in the day is how I live. To make the most of my waking hours, I practice the one-hour rule—a simple habit that helps me learn, reflect, and think. I give myself 60 uninterrupted ...