Have you noticed that as the weather gets warmer, the days get longer? The reverse is true as the weather gets colder: the days grow shorter. Daylight saving time, or summer time, helps us adjust our clocks and our sleep cycles so we have more daylight when we need to be awake.
Clocks are usually set ahead one hour in late March or in April when the sun rises earlier and sets later. We can “lose” the hour because we have lots of daylight to spare. But in the fall and winter, the sun rises later and sets earlier, so clocks are set back one hour in late September or in October to “save” more daylight for when we need to go to work or school. Daylight saving time began during wartime to conserve fuel by reducing the need for artificial light.