On the first Sunday in November, at 2:00 a.m. EDT, clocks are moved back to 1:00 a.m. EST, which results in a 25-hour day.

The boundaries of the Eastern Time Zone have moved westward since the Interstate Commerce Commission (ICC) took over time-zone management from railroads in 1938.

The easternmost and northernmost counties in Kentucky were added to the zone in the 1940s, and in 1961 most of the state went Eastern.

[4] Later, the Energy Policy Act of 2005 extended daylight saving time in the United States, beginning in 2007.

Most of Canada observes daylight saving time synchronously with the United States, with the exception of Saskatchewan, Yukon,[8] and several other very localized areas.

[14] A 2017 consultation paper highlighted the advantage for business and tourism of being in the same time zone as the eastern United States as an important factor in the decision.