Daylight Saving Time (DST) is the biannual practice of shifting clocks forward one hour in the spring and back one hour in the fall, in order to extend daylight hours during waking times. The phrase “spring forward, fall back” is used as a reminder, where an hour is lost in the spring, and that same hour is regained in the fall.
The United States operates on Daylight Saving Time from early March to early November. It remains on Standard Time (ST) for the remainder of the year. The Clock Shift Schedule
In the U.S. and Canada, the rules for the time shift have been standardized since 2007 by the Energy Policy Act of 2005:
Start (“Spring Forward”): Begins on the second Sunday in March at 2:00 a.m. local time. Clocks are advanced to 3:00 a.m., resulting in the loss of one hour of sleep but granting an extra hour of daylight in the evening.
End (“Fall Back”): Ends on the first Sunday in November at 2:00 a.m. local time. Clocks are turned back to 1:00 a.m., meaning an hour of sleep is gained and evening darkness arrives an hour earlier. History & Purpose Daylight Saving Time