First Sunday of April in 1986.
Daylight saving time (DST) or summer time is the practice of advancing clocks during summer months by one hour so that in the evening daylight is experienced an hour longer, while sacrificing normal sunrise times.  The Federal law was amended in 1986 to begin Daylight Saving Time on the first Sunday in April. Under legislation enacted in 1986, Daylight Saving Time in the U.S. began at 2:00 a.m. on the first Sunday of April and ended at 2:00 a.m. on the last Sunday of October. ' An Act to preserve daylight and provide standard time for the United States ' was enacted on March 19, 1918. [See law] It both established standard time zones and set summer DST to begin on March 31, 1918. Daylight Saving Time was observed for seven months in 1918 and 1919. Under legislation enacted in 1986, Daylight Saving Time in the U.S. began at 2:00 a.m. on the first Sunday of April and ended at 2:00 a.m. on the last Sunday of October. The Federal law was amended in 1986 to begin Daylight Saving Time on the first Sunday in April. Under legislation enacted in 1986, Daylight Saving Time in the U.S. began at 2:00 a.m. on the first Sunday of April and ended at 2:00 a.m. on the last Sunday of October. 'An Act to preserve daylight and provide standard time for the United States' was enacted on March 19, 1918. [See law] It both established standard time zones and set summer DST to begin on March 31, 1918. Daylight Saving Time was observed for seven months in 1918 and 1919. As of 2007, daylight time begins in the United States on the second Sunday in March and ends on the first Sunday in November. On the second Sunday in March, clocks are set ahead one hour at 2:00 a.m. local standard time (which becomes 3:00 a.m. local daylight time). On the first Sunday in November, clocks are set back one hour at 2:00 a.m. local daylight time (which becomes 1:00 a.m. local standard time). These dates were established by Congress in the Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005) . Beginning in 2007, daylight time starts on the second Sunday in March and ends on the first Sunday in November. For a very readable account of the history of standard and daylight time in the U.S., see. Ian R. Bartky and Elizabeth Harrison: Standard and Daylight-saving Time, , May 1979 (Vol. 240, No. 5), pp. 46-53. Going from 2007 forward, Daylight Saving Time in the U.S. begins at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November In most of the countries of Western Europe, including the countries that are members of the EU, Daylight Saving Time: begins at 1:00 a.m. 'An Act to preserve daylight and provide standard time for the United States' was enacted on March 19, 1918. [See law] It both established standard time zones and set summer DST to begin on March 31, 1918. Daylight Saving Time was observed for seven months in 1918 and 1919. Daylight Saving Time in Canada. In most of Canada Daylight Saving Time begins at 2:00 a.m. local time on the second Sunday in March. On the first Sunday in November areas on Daylight Saving Time return to Standard Time at 2:00 a.m. local time. When Daylight Saving Time begins turn your clocks ahead one hour But it hasn’t always happened on the second Sunday in March. The Energy Policy Act of 2005, which was implemented in 2007, added four weeks to Daylight Saving Time by changing it to start on the second Sunday in March and end on the first Sunday in November. 7. Often mistakenly called daylight savings time, its official name in the U.S. is Daylight Saving Time
https://en.wikipedia.org/wiki/Daylight_saving_time http://www.webexhibits.org/daylightsaving/e.html http://www.webexhibits.org/daylightsaving/e.html https://answers.yahoo.com/question/index?qid=20061210164232AAvJ9ke http://aa.usno.navy.mil/faq/docs/daylight_time.php https://answers.yahoo.com/question/index?qid=20061210164232AAvJ9ke http://www.timetemperature.com/canada/daylight_saving_time_canada.shtml http://energy.gov/articles/top-8-things-you-didn-t-know-about-daylight-saving-time
when did daylight saving start