Daylight saving time is the practice of moving clocks forward by one hour in spring and back one hour in fall to make better use of natural daylight during evening hours. When daylight saving time begins in March, people “spring forward” by setting their clocks ahead at 2:00 a.m., which means you lose an hour of sleep that night. When it ends in November, people “fall back” by setting clocks back an hour, gaining an extra hour.

The idea is to shift an hour of morning daylight to the evening, when more people are awake and active. During daylight saving time, the sun sets later in the evening, giving families more daylight after school and work.

Not everyone uses daylight saving time. Hawaii and most of Arizona don't observe it, and many countries near the equator don't need it since their daylight hours stay fairly constant year-round. Some people find the twice-yearly time changes disruptive and confusing, especially that groggy morning after springing forward. The proper term is daylight saving time (not “daylight savings time”), though you'll often hear both versions in everyday conversation.