What EST stands for
EST is the abbreviation for Eastern Standard Time. It is five hours behind Coordinated Universal Time, written UTC-5. EST is in effect from the first Sunday of November until the second Sunday of March — roughly the winter half of the year. When people write "EST" as a catch-all for New York time, they are usually reaching for the neutral form ET; strictly, EST names only the standard half of the year.
What EDT stands for
EDT is the abbreviation for Eastern Daylight Time, four hours behind UTC, written UTC-4. It runs from the second Sunday of March to the first Sunday of November — the summer half of the year, when daylight saving time is in effect. It is the same zone as EST, shifted one hour forward.
Is it EST or EDT right now?
The rule is a calendar rule, not a judgement call:
- Second Sunday of March to first Sunday of November → EDT. In 2026, that window is March 8 to November 1.
- First Sunday of November to second Sunday of March → EST. In 2026–27, that window is November 1 to March 14.
The switch happens at 2:00 a.m. local time on each of those Sundays. The full schedule, several years ahead, is on the daylight saving time page. For the live current time in the Eastern zone right now, the clocks on the homepage update every second and follow the transition automatically.
EST vs EDT at a glance
| EST | EDT | |
|---|---|---|
| Full name | Eastern Standard Time | Eastern Daylight Time |
| UTC offset | UTC-5 | UTC-4 |
| In effect | Early November – mid March | Mid March – early November |
| Noon UTC is | 7:00 a.m. | 8:00 a.m. |
| Neutral form | ET — correct in either half of the year | |
| IANA identifier | America/New_York — covers both automatically | |
What "ET" means, and when to use it
ET — Eastern Time — is the neutral form that drops the standard/daylight distinction. It is the right choice for anything open-ended: business hours, a recurring meeting, a broadcast schedule. "Support is open 9 a.m.–5 p.m. ET" is true all year. "9 a.m.–5 p.m. EST" is literally true for only about four months of it.
Use EST or EDT when you are pinning a specific date and the precision matters — a legal filing, a contract deadline, a flight time, a market open. Use ET everywhere else.
Where the Eastern zone applies
Seventeen states and the District of Columbia are entirely on Eastern Time: Connecticut, Delaware, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia and West Virginia. Five more — Florida, Indiana, Kentucky, Michigan and Tennessee — are split between Eastern and Central, with the boundary running along county lines. The US states time zones list has the full breakdown, including which side of each state's line holds which zone.
Common EST and EDT mistakes
- Writing "EST" in July. Eastern Standard Time does not exist in July. The correct forms are EDT, or the neutral ET.
- Assuming EST means "New York time" generally. It means New York time for part of the year.
America/New_Yorkor "ET" means it all year. - Mixing halves across a series. A weekly call announced as "3 p.m. EST" that runs from February into April silently becomes wrong in the second week of March. Announce it as ET.
- Assuming EST is always UTC-5 for a given wall-clock time. It is — but the zone is not. If you store
UTC-5instead ofAmerica/New_York, every future appointment after a transition lands an hour off. - Confusing EDT with EST when converting from UTC. Subtract five hours for EST, four for EDT. Getting this backwards is the single most common conversion error; see UTC and U.S. time for worked examples.
The same pattern in every other zone
Every US zone that observes daylight saving time follows the identical S-for-standard, D-for-daylight pattern: CST and CDT for Central, MST and MDT for Mountain, PST and PDT for Pacific, AKST and AKDT for Alaska. Hawaii uses HST all year because it does not observe DST, and most of Arizona uses MST all year for the same reason. The complete list, including the territories, is on the US time zone abbreviations page.
The one-line rule
If the date falls between the second Sunday of March and the first Sunday of November, write EDT. Otherwise write EST. If there is no fixed date, write ET.
To convert a specific moment between Eastern and any other US zone, use the time zone converter. For the practical side of running meetings across the country, see scheduling across U.S. time zones.