DAYLIGHT TIME PROFILE
Eastern Daylight Time (EDT) Summary
UTC Offset: UTC-4 (4 hours behind GMT)
Active Window: 2nd Sunday March to 1st Sunday November
Standard Counterpart: EST (Eastern Standard Time, UTC-5)
Spring Transition: Spring forward 1 hour (2:00 AM → 3:00 AM)
Fall Transition: Fall back 1 hour (2:00 AM → 1:00 AM)
Eastern Daylight Time (EDT) is the daylight saving time offset observed across eastern North America from March through November. Operating at UTC-4, EDT advances local clocks by one hour relative to winter standard time (EST UTC-5). It governs major financial, business, and broadcasting schedules in New York City, Toronto, Washington D.C., and Atlanta during the spring and summer.
1. What is Eastern Daylight Time (EDT)?
Eastern Daylight Time (EDT) is the summer daylight saving phase of the Eastern Time Zone in North America. When active, EDT maintains an offset of UTC-4, placing local time 4 hours behind Coordinated Universal Time (UTC) and Greenwich Mean Time (GMT).
Daylight Saving Time in the US was first enacted under the Standard Time Act of 1918 to conserve fuel during World War I. The modern schedule was standardized under the Uniform Time Act of 1966 and modified by the Energy Policy Act of 2005, which extended daylight saving time to cover approximately 65% of the calendar year.
Figure 1: Spring Forward Transition Mechanics (EST to EDT)
Figure 1: Visual timeline showing the spring forward clock jump at 2:00 AM on the second Sunday of March, shifting local clocks directly to 3:00 AM EDT.
2. EDT vs. EST: Offset & Seasonal Shift Comparison
Understanding the exact difference between EST and EDT prevents scheduling errors across North American business trips and virtual meetings. For an in-depth guide, visit EST vs EDT Explained.
| Property | Eastern Standard Time (EST) | Eastern Daylight Time (EDT) |
|---|---|---|
| UTC Offset | UTC-5 (5 hours behind GMT) | UTC-4 (4 hours behind GMT) |
| Season | Winter (November – March) | Summer (March – November) |
| Sunlight Focus | Standard morning sunrise synchronization | Extended evening daylight hours |
| Time Difference to London | 5 hours behind GMT (London winter) | 5 hours behind BST (London summer) / 4 hours behind GMT |
3. Daylight Saving Transition Calendar & Rules
In accordance with US federal law, the annual transition dates follow strict calendar rules:
- Spring Transition (EST to EDT): Second Sunday of March at 2:00 AM. Clocks are set forward 1 hour to 3:00 AM EDT (losing 1 hour of sleep).
- Autumn Transition (EDT to EST): First Sunday of November at 2:00 AM. Clocks are set back 1 hour to 1:00 AM EST (gaining 1 hour of sleep).
For international transition schedules, refer to our comprehensive guide on Daylight Saving Time Explained.
4. Geographic Coverage & Non-DST Exceptions
Eastern Daylight Time covers major commercial regions across North America:
- United States: New York, Massachusetts, Pennsylvania, Florida (majority), Georgia, Ohio, North Carolina, Virginia, Michigan (majority). See USA Time Zones.
- Canada: Ontario (Toronto, Ottawa), Quebec (Montreal), Nunavut. See Canada Time Zones.
- Exceptions (No DST): Panama, Jamaica, and the Cayman Islands remain on UTC-5 year-round, matching EST in winter but running 1 hour behind EDT during summer.
5. Global EDT Time Conversion Tables
Below is a reference conversion table for Eastern Daylight Time (EDT, UTC-4) during summer months:
| EDT (UTC-4) | GMT (UTC+0) EDT to GMT | BST (UTC+1) EDT to BST | PDT (UTC-7) EDT to PDT | CEST (UTC+2) EDT to CEST | IST (UTC+5:30) EDT to IST |
|---|---|---|---|---|---|
| 00:00 EDT (Midnight) | 04:00 GMT | 05:00 BST | 21:00 PDT (Prev Day) | 06:00 CEST | 09:30 IST |
| 06:00 EDT | 10:00 GMT | 11:00 BST | 03:00 PDT | 12:00 CEST | 15:30 IST |
| 09:00 EDT | 13:00 GMT | 14:00 BST | 06:00 PDT | 15:00 CEST | 18:30 IST |
| 12:00 EDT (Noon) | 16:00 GMT | 17:00 BST | 09:00 PDT | 18:00 CEST | 21:30 IST |
| 15:00 EDT | 19:00 GMT | 20:00 BST | 12:00 PDT | 21:00 CEST | 00:30 IST (Next Day) |
| 18:00 EDT | 22:00 GMT | 23:00 BST | 15:00 PDT | 00:00 CEST (Next Day) | 03:30 IST (Next Day) |
For live conversions, use our interactive GMT to EST/EDT Time Calculator.
Figure 2: Global Offsets During Northern Hemisphere Summer
Figure 2: Relative time offset comparison showing EDT (UTC-4) alongside PDT (UTC-7), BST (UTC+1), and CEST (UTC+2) during summer months.
6. Stock Exchange Hours, Server Infrastructure & Broadcasting
During EDT, trading on the NYSE and NASDAQ operates from 9:30 AM to 4:00 PM EDT. Because European stock exchanges (LSE in London, Euronext in Paris) are on BST (UTC+1) and CEST (UTC+2), European traders monitor Wall Street opening bells at 2:30 PM London time / 3:30 PM Paris time.
For cloud software engineers, handling the transition into EDT requires ensuring servers log timestamps in UTC to avoid duplicating scheduled jobs during clock shifts. Read our developer guide on JavaScript Time Zone Handling for code examples.
7. Frequently Asked Questions (EDT)
What does EDT stand for?
EDT stands for Eastern Daylight Time. It is the daylight saving time offset (UTC-4) used in the Eastern Time zone of North America during the spring, summer, and early autumn months.
What is the UTC offset for EDT?
The UTC offset for Eastern Daylight Time (EDT) is UTC-4. Local time in the EDT zone is exactly 4 hours behind Coordinated Universal Time (UTC) and Greenwich Mean Time (GMT).
When is EDT active during the year?
EDT is active from the second Sunday of March (when clocks 'spring forward' from 2:00 AM to 3:00 AM) until the first Sunday of November (when clocks 'fall back' from 2:00 AM to 1:00 AM standard time).
Which major cities observe Eastern Daylight Time?
Major North American metropolitan areas observing EDT during summer months include New York City, Toronto, Washington D.C., Montreal, Miami, Atlanta, Boston, Philadelphia, and Detroit.
What is the difference between EDT and EST?
EDT (Eastern Daylight Time) is UTC-4, observed during the summer months when daylight saving time is active. EST (Eastern Standard Time) is UTC-5, observed during the winter months when standard time is in effect.
How far behind GMT is EDT?
EDT is 4 hours behind Greenwich Mean Time (GMT/UTC+0). When it is 12:00 PM (noon) GMT in London, it is 8:00 AM EDT in New York or Toronto. Note that if London is observing British Summer Time (BST, UTC+1), London is 5 hours ahead of EDT.
Why do we switch from EST to EDT?
The transition from EST to EDT advances local clocks by one hour during warmer months to extend evening daylight hours, reducing energy consumption for residential lighting and encouraging evening commerce and outdoor activity.
How do I convert EDT to Pacific Daylight Time (PDT)?
Eastern Daylight Time (EDT, UTC-4) is 3 hours ahead of Pacific Daylight Time (PDT, UTC-7). To convert EDT to PDT, subtract 3 hours (e.g., 2:00 PM EDT equals 11:00 AM PDT).
How do I convert EDT to Central Daylight Time (CDT)?
Eastern Daylight Time (EDT, UTC-4) is 1 hour ahead of Central Daylight Time (CDT, UTC-5). To convert EDT to CDT, subtract 1 hour (e.g., 10:00 AM EDT equals 9:00 AM CDT).
Do all regions in the Eastern Time Zone switch to EDT?
Most US states and Canadian provinces in the Eastern Time Zone switch to EDT. However, tropical regions within the Eastern zone—such as Jamaica, Panama, and the Cayman Islands—do not observe DST and remain on UTC-5 (EST) year-round.
Does the stock market change trading hours during EDT?
No. The New York Stock Exchange (NYSE) and NASDAQ maintain fixed local operating hours from 9:30 AM to 4:00 PM Eastern Time. When local time shifts to EDT (UTC-4), the exchanges shift along with it, altering their absolute offset to London and Tokyo.
What is the time difference between EDT and Central European Summer Time (CEST)?
Central European Summer Time (CEST, UTC+2) is 6 hours ahead of Eastern Daylight Time (EDT, UTC-4). When it is 10:00 AM EDT in New York, it is 4:00 PM CEST in Paris and Berlin.
What is the time difference between EDT and India Standard Time (IST)?
India Standard Time (IST, UTC+5:30) is 9 hours and 30 minutes ahead of Eastern Daylight Time (EDT, UTC-4). When it is 8:00 AM EDT in New York, it is 5:30 PM IST in New Delhi and Mumbai.
What is the time difference between EDT and Australian Eastern Standard Time (AEST)?
Australian Eastern Standard Time (AEST, UTC+10) is 14 hours ahead of Eastern Daylight Time (EDT, UTC-4). When it is 8:00 AM EDT in New York, it is 10:00 PM AEST in Brisbane.
What happens to the missing hour during the spring transition to EDT?
On the second Sunday of March at 2:00 AM, clocks jump directly to 3:00 AM EDT. The 2:00 AM to 2:59 AM hour is skipped entirely, resulting in a 23-hour calendar day.
How does EDT impact flight schedules and airline tickets?
Flight itineraries display local departure and arrival clock times. Because flight planning software calculates flight durations using UTC UTC-4 offsets during EDT, published flight durations remain accurate across DST transitions.
What is the Sunshine Protection Act and how would it affect EDT?
The Sunshine Protection Act is proposed US federal legislation that would make Daylight Saving Time (EDT, UTC-4) permanent year-round, eliminating the annual fall transition back to standard time (EST, UTC-5).
How do software systems handle the EDT clock change?
Modern software applications store timestamps in UTC (which never changes for DST) and rely on timezone libraries (such as IANA `America/New_York`) to automatically calculate EDT offset shifts on client devices.
Is EDT the same as Eastern Time?
EDT is the specific summer phase (UTC-4) of Eastern Time. Eastern Time (ET) is the generic geographic umbrella term that covers both EST (winter) and EDT (summer).
What is the best time for a conference call between London and New York during EDT?
During the summer when London observes BST (UTC+1) and New York observes EDT (UTC-4), there is a 5-hour time difference. The optimal meeting window is between 9:00 AM – 12:00 PM EDT (2:00 PM – 5:00 PM BST).