Daylight Saving Time 2021: When do we change our clocks? Updated Mar 14, 2021; Posted Mar 13, 2021 Electric Time technician Dan LaMoore admires a 1000-lb., 12-foot diameter clock constructed for a resort in Vietnam, Tuesday, March 9, 2021, in Medfield, Mass. Daylight saving time begins at 2 a.m. local time Sunday, March 14, 2021, when clocks are set ahead one hour. (AP Photo/Elise Amendola) AP Facebook Share Daylight Saving Time begins on Sunday, March 14. Clocks are turned forward an hour at 2 a.m. to 3 a.m., meaning we lose an hour of sleep if we wake up to an alarm set for Sunday morning. The benefit? Sunrise will be an hour later, just before 7 a.m. in Massachusetts, instead of around 6 a.m. As the days continue, the evenings will continue to be brighter.