Daylight saving time (DST) is the practice of advancing clocks during warmer months so that evenings have more daylight and mornings have less. The exact dates of DST vary by country, but it is typically observed from March to November in the Northern Hemisphere and from September to April in the Southern Hemisphere.
DST was first proposed in the late 18th century by Benjamin Franklin, but it was not widely adopted until the early 20th century. Today, DST is used in over 70 countries around the world.