Eastern Daylight Time (EDT)
UTC offset: -04:00
Standard offset: -05:00 (EST)
IANA identifier: America/New_York
Abbreviation: EDT
Population affected: approximately 150 million (US and Canada combined)
DST period: Second Sunday in March to first Sunday in November
Eastern Daylight Time is the summer clock for the most economically significant time zone in the Western Hemisphere. When EDT is active, clocks read one hour ahead of Eastern Standard Time, placing the zone at UTC-04:00. This shift affects roughly 150 million people across the eastern United States and Canada, including the financial capital (New York), the political capital (Washington DC), and the largest Canadian city (Toronto).
EDT runs from the second Sunday in March (clocks spring forward at 2:00 a.m.) to the first Sunday in November (clocks fall back at 2:00 a.m.). That's roughly 8 months of DST and 4 months of standard time, meaning EDT is actually the "normal" state for most of the year.
The Economic Engine
Wall Street opens at 9:30 a.m. EDT. That single fact drives global scheduling. European traders adjust their day around the New York open. Asian markets close before it. When the NYSE bell rings, London is at 2:30 p.m. BST, Tokyo has gone home, and the West Coast is still drinking coffee at 6:30 a.m. PDT.
The Eastern Time Zone generates the largest share of US GDP. The financial sector (New York), the federal government (Washington), technology hubs (parts of Virginia, North Carolina's Research Triangle), media (New York, Atlanta's CNN), and healthcare giants are all on EDT in summer.
Major Cities
New York City (~8.3 million, metro ~20 million): The city that defines the timezone. Global finance, media, fashion, arts. Times Square's countdown on New Year's Eve is the nation's clock-watching event.
Washington, DC (~700,000, metro ~6 million): Federal government, embassies, think tanks, lobbying firms. The city's schedule ripples through national policy and international diplomacy.
Toronto (~2.9 million, metro ~6.2 million): Canada's largest city and financial center. Bay Street operates on the same schedule as Wall Street.
Miami (~450,000, metro ~6 million): Gateway to Latin America. Banking, trade, tourism, cruise ships. The city functions as a bridge between EDT and Caribbean/South American time zones.
Atlanta (~500,000, metro ~6 million): CNN headquarters, Delta Airlines hub, major logistics center. The busiest airport in the world (Hartsfield-Jackson) operates on EDT.
Philadelphia, Boston, Montreal, Detroit (yes, Michigan is Eastern), Charlotte, and Columbus round out the major cities.
Geographic Extent
EDT covers:
- 17 US states entirely
- Parts of 6 additional states (Indiana was famously split until 2006)
- Ontario and Quebec (most of)
- Parts of Nunavut
The zone stretches from the tip of Maine to the Florida Keys, and from the Atlantic coast to the Indiana-Illinois border. It's the most populous US time zone.
The DST Debate
The US has periodically debated eliminating the time change. The Sunshine Protection Act (passed the Senate in 2022 but stalled in the House) proposed permanent DST. Proponents argue the November "fall back" causes depression and traffic accidents. Opponents (including sleep scientists) prefer permanent standard time, arguing morning darkness is worse for health. As of now, the twice-yearly change persists.
Broadcasting and Media
Prime-time television in the US is defined by Eastern Time. "8 PM Eastern" is the anchor for network scheduling. Live events (awards shows, sports) reference Eastern Time first. This creates the odd situation where West Coast viewers see "spoilers" from Eastern Time audiences three hours earlier.
Sports
Major professional leagues schedule around Eastern Time:
- NFL: Sunday 1:00 PM and 4:25 PM EDT kickoffs
- NBA/NHL: 7:00 PM or 7:30 PM EDT starts
- MLB: varies, but marquee games target EDT prime time
Scheduling
At UTC-04:00 (EDT):
- Central (CDT): 1 hour behind
- Mountain (MDT): 2 hours behind
- Pacific (PDT): 3 hours ahead (behind*)
- London (BST): 5 hours ahead
- Paris (CEST): 6 hours ahead
- Tokyo (JST): 13 hours ahead
Neighboring Zones
| Zone | Offset | Difference from EDT |
|---|---|---|
| Atlantic (ADT) | UTC-03:00 | 1 hour ahead |
| Central (CDT) | UTC-05:00 | 1 hour behind |
| Newfoundland (NDT) | UTC-02:30 | 1.5 hours ahead |
| UK (BST) | UTC+01:00 | 5 hours ahead |
| Cuba (CDT) | UTC-04:00 | Same |
| Brazil (Brasilia) | UTC-03:00 | 1 hour ahead |
Technical Identifiers
- America/New_York (IANA canonical)
- EDT (Eastern Daylight Time)
- EST (winter: Eastern Standard Time, UTC-05:00)
- Windows: "Eastern Standard Time" (name covers both EST and EDT)
- DST rule: 2nd Sunday March, 1st Sunday November (since 2007)
- Military/aviation: R ("Romeo") for UTC-04:00
Quick Reference
| Attribute | Value |
|---|---|
| UTC offset (summer) | -04:00 |
| UTC offset (winter) | -05:00 |
| DST observed | Yes |
| IANA zone | America/New_York |
| Population | ~150 million |
| Key cities | NYC, DC, Toronto, Miami, Atlanta |
| Wall Street open | 9:30 AM EDT |
| Same summer offset as | Atlantic Standard, Cuba CDT |
| Prime-time TV | 8:00 PM EDT |
| DST months | ~8 (March-November) |