Daylight saving time (DST) is the practice of advancing clocks during warmer months so that evenings have more daylight and mornings have less. Daylight saving time is observed in many countries around the world, but the specific dates vary by country and region. In the United States, daylight saving time begins on the second Sunday in March and ends on the first Sunday in November. So, in 2025, daylight saving time will begin on Sunday, March 9 and end on Sunday, November 2.
Daylight saving time was first proposed in the 18th century by Benjamin Franklin, but it was not widely adopted until the 20th century. During World War I, many countries adopted DST as a way to conserve energy. After the war, some countries continued to observe DST, while others abandoned it. In the United States, DST was first adopted in 1918, but it was not until 1966 that it became a permanent practice.