Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Eastern Daylight Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
Second Sunday in March at 02:00 AM (Clocks advance 1 hour to EDT)
⬇️ Fall Back (Clocks Return)
First Sunday in November at 02:00 AM (Clocks turn back 1 hour to EST)
Observing Jurisdictions & Subdivisions
5 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under EDT:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
London and New York share about four hours of common trading in the European afternoon and American morning.
Local Hours: 09:30 - 16:00 EDT
UTC Window: 13:00 - 21:00 UTC
Local Hours: 09:30 - 16:00 EDT
UTC Window: 13:00 - 21:00 UTC
Local Hours: 09:30 - 16:00 EDT
UTC Window: 13:00 - 21:00 UTC
Major Cities in EDT
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1918
First signed into law during World War I by President Woodrow Wilson to save coal. Congress repealed it after the war due to farm lobby pressure, but President Franklin D. Roosevelt brought year-round 'War Time' back in 1942. The modern annual schedule was standardized by the Uniform Time Act of 1966.
On the second Sunday in March at 2:00 AM, clocks jump straight to 3:00 AM, making that calendar day only 23 hours long.
Frequently Asked Questions about EDT
What does EDT stand for?
EDT stands for Eastern Daylight Time, which runs at UTC-4 from early spring through autumn.
When does EDT start and end?
In the United States and Canada, clocks shift into EDT on the second Sunday of March and return to EST on the first Sunday of November.
What is the difference between EDT and EST?
EDT is four hours behind Greenwich (UTC-4) during summer, while EST is five hours behind (UTC-5) during winter.