What if we only had twenty-three hours in a day? We do - one day each year. On the second Sunday in March, many of us move our clocks one hour forward. We "lose" one hour of time. That day has only twenty-three hours.
We "gain" that hour back in November when we set our clocks back one hour. The first Sunday in November has twenty-five hours! This is called Daylight Saving Time (DST). We say "spring forward, fall back" to help us remember how to change our clocks. The official change of time happens at 2 a.m.
Many countries around the world change their clocks, too. In Europe, it is called Summer Time. Some countries do not. Not even all places in the U.S. change their clocks. Many people say the change is silly. They wish the time stayed the same all year long. They say that we are really not saving daylight. They say we are really not saving energy.