When Does the Clock Time Change Occur?

Daylight savings time changes the time twice per year to increase the duration of daylight hours into the evening during part of the year. Daylight savings time was first proposed by Benjamin Franklin.

Spring Forward

On the second Sunday of March at 2 a.m., the clock time goes forward one hour to 3 a.m.

Fall Back

On the first Sunday of November at 2 a.m., the clock time goes back one hour to 1 a.m.

Purpose

Daylight savings time saves energy by reducing the number of hours between sunset and the time people go to bed because people use the most energy after sunset.

History

The first use of daylight savings time in the United States occurred during World War I but was repealed after the war ended. The U.S. government issued the Uniform Time Act of 1966 to standardize, but not require the use of, daylight savings time across the country.

Exceptions

The clock change does not occur in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and most of Arizona. These regions use standard time the entire year.

References

• California Energy Commission: Daylight Savings Time
• USNO: Daylight Time