When Does Daylight Saving Time Start and End in the US?

When do the clocks go forward and back in Washington, D.C.?

Clocks in the United States spring forward on the second Sunday of March. They fall back on the first Sunday of November.

Both changes happen at 2:00 a.m. local time. Spring forward: 2:00 a.m. becomes 3:00 a.m. You lose one hour of sleep. Fall back: 2:00 a.m. becomes 1:00 a.m. You gain one hour.

The DST period lasts about 34 weeks. Standard time covers the remaining 18.

Why 2:00 a.m.?

Two in the morning was chosen for minimum disruption. Few trains run. Few flights depart. Most businesses are closed. Shifting the hour at 2:00 a.m. avoids pushing the change into the previous calendar day, which would happen at midnight.

The autumn change creates a genuine ambiguity. When clocks fall back to 1:00 a.m., the hour between 1:00 a.m. and 2:00 a.m. happens twice. Any timestamp recorded during that window in local time is ambiguous. In spring, the opposite occurs: the hour from 2:00 a.m. to 3:00 a.m. does not exist. A 2:30 a.m. alarm on the second Sunday of March will not ring.

What happens during the March change?

On the second Sunday of March at 2:00 a.m., clocks move forward to 3:00 a.m. Eastern Daylight Time (EDT, UTC−4) replaces Eastern Standard Time (EST, UTC−5). The same shift happens in all observing zones.

For Washington, D.C. on the March equinox (20 March 2026), sunrise is at 07:13 and sunset at 19:19: 12 hours and 6 minutes of daylight.

What happens during the November change?

On the first Sunday of November at 2:00 a.m., clocks move back to 1:00 a.m. EDT becomes EST again.

For Washington, D.C. on the December solstice (21 December 2026), sunrise is at 07:22 and sunset at 16:49: only 9 hours and 26 minutes of daylight. On the June solstice (21 June 2026), the city gets 14 hours and 54 minutes of daylight, with sunrise at 05:42 and sunset at 20:36.

DST dates for the next five years

The 2007 extension

Before 2007, DST started on the first Sunday of April and ended on the last Sunday of October. The 2005 Energy Policy Act shifted the start to the second Sunday of March and the end to the first Sunday of November. The change took effect in 2007 and added roughly four weeks of daylight saving time.

This is not the first time the US has extended DST. Congress put the entire country on permanent DST in 1973 during the energy crisis. The experiment was abandoned after one winter. Dark mornings caused a public backlash, especially from parents of schoolchildren waiting for buses in darkness.

Losing an hour in March

Spring forward means you lose one hour. If you normally wake up at 7:00 a.m., on the Sunday of the change your body will think it is 6:00 a.m. Traffic accidents and heart attacks increase in the days following the spring transition, according to chronobiology studies.

Gaining an hour in November

Fall back means you gain one hour. If you normally wake up at 7:00 a.m., on that Sunday your body will think it is 8:00 a.m. Bars in some states get an extra hour of service: they close at 2:00 a.m., but the clocks go back to 1:00 a.m., so the hour repeats.

Which clocks change themselves?

Phones, laptops, tablets, and streaming boxes update automatically. They read their offset from a time zone database that contains the rule.

Everything else is manual. Car dashboards, ovens, microwaves, wall clocks, wristwatches, and older alarm clocks need to be reset by hand. Same for some thermostats and security panels. Check any device that controls something on a schedule.

Which places skip DST?

Two states opt out entirely: Arizona (except the Navajo Nation) and Hawaii. Most US territories also stay on standard time year-round. Puerto Rico, the US Virgin Islands, Guam, the Northern Mariana Islands, and American Samoa do not observe DST.

What to check when the clocks change

• Second Sunday March: Set clocks forward from 2:00 a.m. to 3:00 a.m.
• First Sunday November: Set clocks back from 2:00 a.m. to 1:00 a.m.
• Manual devices: Car, oven, microwave, wall clock, thermostat, alarm clock, security panel.
• Automatic devices: Phone, laptop, tablet, streaming device.