The terms “spring forward” and “fall back” are used to describe a practice of changing standard time with the intention of “saving” (as in, making better use of) natural light. During daylight savings time (DST), clocks are turned ahead one hour, so that the sun rises later in the morning and sets later in the evening.

Why does spring forward exist?

The main purpose of Daylight Saving Time (called "Summer Time" in many places in the world) is to make better use of daylight. We change our clocks during the summer months to move an hour of daylight from the morning to the evening. Countries have different change dates. ... According to some sources, DST saves energy.

What is the reason for daylight savings time?

The nominal reason for daylight saving time has long been to save energy. The time change was first instituted in the U.S. during World War I, and then reinstituted again during WW II, as a part of the war effort.