Daylight Saving Time Starts Countdown 2027

Daylight Saving Time starts on the second Sunday of March at 2:00 a.m. local time: the clock jumps straight to 3:00 a.m. The night is only 23 hours long and you lose an hour of sleep. Because the rule is stated in local time, the change does not happen simultaneously across the country — each time zone springs forward when its own 2 a.m. arrives.

The dates differ from Europe's. The United States moves three weeks earlier in spring and one week later in autumn than the EU. For those few weeks the usual gap between New York and London narrows from five hours to four — a recurring trap for scheduled international calls.

Where it does not apply. Hawaii and most of Arizona stay on standard time all year, as do Puerto Rico, Guam and the US Virgin Islands. The Navajo Nation, which extends across Arizona, does observe the change.

Why the second Sunday of March? The Energy Policy Act of 2005 extended the period, moving the start from April to March from 2007 onwards. The original justification was energy saving; studies since have found the effect small and sometimes negative, as reduced lighting demand is offset by heating and air conditioning.

Attempts to make it permanent have repeatedly stalled in Congress. The country has tried year-round DST before — in 1974, during the oil crisis — and abandoned it within months, largely because of dark winter school runs.