EST is Eastern Standard Time (UTC−5), used in winter; EDT is Eastern Daylight Time (UTC−4), used in summer. Eastern time is on EDT now and switches to EST at 2:00 a.m. on Sunday, November 1, 2026, then back to EDT on Sunday, March 14, 2027.
Both labels describe the same clock in New York, Atlanta or Miami; the letter in the middle says which half of the year you’re in. The same pattern applies to every US zone that observes daylight saving time: CST and CDT, MST and MDT, PST and PDT. This guide lists all the US zones with their offsets, the switch dates, the places that never change, and when to write EST, EDT or simply ET.
EST vs EDT at a glance
| EST | EDT | |
|---|---|---|
| Full name | Eastern Standard Time | Eastern Daylight Time |
| Offset from UTC | UTC−5 | UTC−4 |
| 2026–2027 period | November 1, 2026 to March 14, 2027 | March 8 to November 1, 2026, and March 14 to November 7, 2027 |
| Noon in New York equals | 17:00 UTC | 16:00 UTC |
Under federal law, 15 U.S.C. 260a, daylight time starts at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November. That’s why EDT covers about eight months of the year and EST only about four.
All US time zones and their abbreviations
Federal law names nine standard time zones and defines each one as an offset from Coordinated Universal Time (15 U.S.C. 261 and 263). The Secretary of Transportation sets the boundaries between them.
| Zone | Standard time | Daylight time | Example places |
|---|---|---|---|
| Atlantic | AST, UTC−4 | Not used | Puerto Rico, US Virgin Islands |
| Eastern | EST, UTC−5 | EDT, UTC−4 | New York, Washington, D.C., Atlanta, Miami |
| Central | CST, UTC−6 | CDT, UTC−5 | Chicago, Dallas, Houston, New Orleans |
| Mountain | MST, UTC−7 | MDT, UTC−6 | Denver, Salt Lake City; Phoenix stays on MST |
| Pacific | PST, UTC−8 | PDT, UTC−7 | Los Angeles, San Francisco, Seattle, Las Vegas |
| Alaska | AKST, UTC−9 | AKDT, UTC−8 | Anchorage, Fairbanks, Juneau |
| Hawaii-Aleutian | HST, UTC−10 | HDT, UTC−9 (Aleutian Islands only) | Honolulu (no daylight time), Adak |
| Samoa | SST, UTC−11 | Not used | American Samoa |
| Chamorro | ChST, UTC+10 | Not used | Guam, Northern Mariana Islands |
The offsets in the daylight column are one hour less behind UTC, because clocks move forward in March. Puerto Rico’s AST is the same clock time as EDT in summer, but it never changes, so in winter it is one hour ahead of New York.
When the switch happens: 2026 to 2028
| Year | EST → EDT (clocks forward) | EDT → EST (clocks back) |
|---|---|---|
| 2026 | Sunday, March 8, 2026 | Sunday, November 1, 2026 |
| 2027 | Sunday, March 14, 2027 | Sunday, November 7, 2027 |
| 2028 | Sunday, March 12, 2028 | Sunday, November 5, 2028 |
Every zone changes at 2:00 a.m. local time, so the switch moves west across the country an hour at a time. Our daylight saving time guide covers the history of the rule, the full list through 2030 and the weeks when US and European clocks are out of step. To see how long you have until the next change, check the days until daylight saving time ends countdown.
Arizona, Hawaii and the territories
A state that lies within one time zone may exempt itself from daylight saving time, but only by keeping the whole state on standard time all year. According to NIST, daylight time isn’t observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands or Arizona, except for the Navajo Nation, which does observe it.
- Arizona: stays on MST (UTC−7) all year. In summer that lines up with Pacific daylight time, so Phoenix shows the same time as Los Angeles; in winter it matches Denver.
- Hawaii: stays on HST (UTC−10). It is 5 hours behind New York in winter and 6 hours behind in summer.
- The Navajo Nation: follows MDT in summer, so in northeastern Arizona the time can change when you cross a reservation boundary.
EST, EDT or ET: which should you write?
The most common mistake is writing EST for a summer event. A webinar listed as “2:00 p.m. EST” in July is, strictly, an hour off: 2:00 p.m. EST is 3:00 p.m. on New York clocks at that time of year. Most readers will guess what you meant, but software that reads the label literally won’t.
- Write ET (Eastern Time) when you mean “whatever New York’s clock says on that date”. It’s correct all year and widely used in schedules and listings. The same goes for CT, MT and PT.
- Write EST or EDT only when you mean that specific offset, and check it matches the date.
- Write a UTC offset, such as 14:00 UTC−4, for technical or international audiences. Our UTC vs GMT guide explains why UTC is the safer reference.
Converting between US zones
Because the mainland zones all change on the same night, the gaps between them stay the same all year. Eastern is 1 hour ahead of Central, 2 ahead of Mountain and 3 ahead of Pacific, so 9:00 a.m. ET is 6:00 a.m. PT whether it’s January or July. Ready-made charts: Eastern to Pacific time and Eastern to Central time.
The gap does change for places that don’t switch. Arizona is 2 hours behind New York in winter and 3 hours behind in summer, and Hawaii goes from 5 hours behind to 6. For any pair of places on a particular date, the time zone converter applies that date’s offsets for you.
Frequently asked questions
Is it EST or EDT right now?
From the second Sunday in March to the first Sunday in November it’s EDT; the rest of the year it’s EST. In 2026, Eastern time is on EDT until 2:00 a.m. on Sunday, November 1, then on EST until March 14, 2027.
What is the difference between EST and EDT?
One hour. EST is UTC−5 and EDT is UTC−4. Clocks move forward an hour from EST to EDT in March and back in November.
Is New York on EST or EDT?
Both, at different times of the year. New York observes daylight saving time, so it uses EDT in summer and EST in winter.
Does Arizona use PST or MST?
Most of Arizona uses MST all year. In summer, when California moves to PDT, Arizona’s clocks show the same time as California’s.
Is ET the same as EST?
Only in winter. ET means the local time in the Eastern zone, which is EST in winter and EDT in summer.