When does Daylight Saving Time begin and end?

Per the Energy Policy Act of 2005, Daylight Saving Time was extended to begin the second Sunday in March and end the first Sunday of November. This change went into effect in 2007.

2017 - DST begins March 12, ends November 5
2018 - DST begins March 11, ends November 4
2019 - DST begins March 10, ends November 3
2020 - DST begins March 8, ends November 1

For more information see the U.S. Naval Observatory site.