Many countries change their clock twice a year to observe day light saving time. The date of Daylight Savings Time Starts and Ends may vary with year to year and also depends on location.
In United States DST starts on the second Sunday of March at 01:00 AM by setting clocks ahead to 02:00 AM. And it ends on the first Sunday of November at 02:00 AM by setting clocks back to 01:00 AM. DST 2017 will begin on 12th March 2017 and will end on 5th November.
Not all places in the U.S. observe daylight time. In particular, Hawaii and most of Arizona do not use it. The most recent change to local daylight time policy was in 2006, when Indiana adopted the use of daylight time state-wide.
Here's a brief calendar of the time change from Navy.mil.
Of interest, Read CNN's Fast Facts for background information about Daylight Saving Time.