EST vs EDT: The One-Letter Difference That Moves Your Meeting an Hour
EST (Eastern Standard Time) is UTC-5 and applies from early November to early March. EDT (Eastern Daylight Time) is UTC-4 and applies the rest of the year — March 8 through November 1 in 2026. Same cities, same time zone; only the offset from UTC changes, by exactly one hour, twice a year.
The letter matters when you convert. 3:00 p.m. EST is 20:00 UTC; 3:00 p.m. EDT is 19:00 UTC. Label a July meeting "EST" and anyone converting carefully arrives an hour off. If you'd rather not track which one applies, write "ET" — it means whichever offset is currently in effect — and let a date-aware converter do the arithmetic.
Need one specific time converted? The UTC to EST converter applies the correct EST or EDT offset for any date.
Open UTC to EST Converter →EST and EDT at a Glance
The cities you probably schedule against — New York, Toronto, Miami, Atlanta, Boston — use both abbreviations, switching twice a year. Despite "standard" being in the name, EST is the minority case: it covers about four months of the year, EDT about eight.
| EST | EDT | |
|---|---|---|
| Full name | Eastern Standard Time | Eastern Daylight Time |
| UTC offset | UTC-5 | UTC-4 |
| In effect | Early November to early March | Early March to early November (Mar 8 – Nov 1 in 2026) |
| Noon in New York | 17:00 UTC | 16:00 UTC |
| Share of the year | About 35% | About 65% |
Switch Dates Through 2029
US clocks spring forward on the second Sunday of March and fall back on the first Sunday of November, both at 2:00 a.m. local time. In spring, 2:00 a.m. becomes 3:00 a.m. and you lose an hour; in fall, 2:00 a.m. becomes 1:00 a.m. and you get it back. These dates match the IANA time zone database:
| Year | EST → EDT (spring forward) | EDT → EST (fall back) |
|---|---|---|
| 2025 | March 9 | November 2 |
| 2026 | March 8 | November 1 |
| 2027 | March 14 | November 7 |
| 2028 | March 12 | November 5 |
| 2029 | March 11 | November 4 |
The schedule comes from federal law: the Uniform Time Act of 1966 put daylight saving on a national calendar, and the Energy Policy Act of 2005 set the current March–November window, in effect since 2007.
EST and EDT to UTC: Conversion Table
To convert Eastern time to UTC, add 5 hours during EST and 4 hours during EDT. Going from UTC to Eastern, subtract. Here is the working day, both ways the year can go:
| Eastern time | UTC during EST (Nov–Mar) | UTC during EDT (Mar–Nov) |
|---|---|---|
| 6:00 a.m. | 11:00 | 10:00 |
| 9:00 a.m. | 14:00 | 13:00 |
| 12:00 p.m. | 17:00 | 16:00 |
| 3:00 p.m. | 20:00 | 19:00 |
| 5:00 p.m. | 22:00 | 21:00 |
| 8:00 p.m. | 01:00 (next day) | 00:00 (next day) |
| 11:00 p.m. | 04:00 (next day) | 03:00 (next day) |
Watch the date rollover: from 7:00 p.m. EST or 8:00 p.m. EDT onward, the UTC timestamp lands on the next calendar day. That is how a Monday-evening deadline in New York shows up as Tuesday in a server log. For one specific date and time, the converter on this site does the offset lookup for you.
Why a June Invite Marked "EST" Is an Hour Off
In June, every clock on the East Coast runs on EDT. An invite that says "2:00 PM EST" in June describes a time no clock in New York actually shows: 2:00 p.m. EST is 19:00 UTC, which is 3:00 p.m. on that June afternoon in Manhattan.
Most people who write it mean "2:00 p.m. New York time," and most calendar apps quietly ignore the label because events are stored against a time zone, not an abbreviation. The failure shows up in manual conversion. A colleague in Berlin takes the label at face value, adds 5 hours to get 19:00 UTC instead of the intended 18:00, converts to local time, and joins the call an hour late.
The fix is free: write "ET," which means whichever offset is in effect on the day, or put the UTC time in the invite alongside the local one.
Software Doesn't Use EST or EDT — It Uses America/New_York
Time zone abbreviations are display strings, not identifiers. Software that handles time correctly stores the IANA zone ID America/New_York and resolves the offset from the date: a timestamp on July 16 resolves to UTC-4, one on January 16 to UTC-5. The IANA time zone database carries the complete rule history — including every past change to the US switch dates — which is why software can also interpret a 2005 timestamp correctly, back when the window was different.
Two habits follow. Store and exchange machine timestamps in UTC or with an IANA zone ID, never with a three-letter abbreviation. And when writing times for people, prefer "ET": it is correct in January and in July.
Who Switches, and Who Never Does
The whole Eastern zone across the US and most of eastern Canada — New York, Toronto, Miami, Atlanta, Boston — moves between EST and EDT automatically. Three US carve-outs never do:
- Arizona stays on Mountain Standard Time (UTC-7) all year — except the Navajo Nation, which does observe DST.
- Hawaii stays on Hawaii Standard Time (UTC-10).
- The US territories — Puerto Rico, the US Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands — all skip DST.
Puerto Rico shows why abbreviations mislead. It sits at UTC-4 year-round on Atlantic Standard Time: in summer its clocks match Miami's, in winter it runs an hour ahead. Same offset as New York for most of the year, but never "on EDT."
Frequently asked questions
Is EST always 5 hours behind UTC?
Yes. EST means UTC-5 by definition, on any date. What changes is whether Eastern cities actually use it: from November to March they do, and from March to November they run on EDT (UTC-4) instead. So a timestamp labeled EST always converts the same way — add 5 hours to get UTC — even if the label was applied in July by mistake. That fixed meaning is exactly why summer "EST" labels cause hour-off errors.
Should I write ET, EST, or EDT?
Write ET unless you have a reason not to. ET means Eastern Time — whichever of EST or EDT is in effect on that date — so it is never wrong. Use EST or EDT only when the specific offset matters, such as documenting a log timestamp or a contract deadline, and you have checked the date against the switch calendar. For anything recurring, a zone ID like America/New_York beats all three.
What happens to clocks at 2 a.m. on the changeover?
On the second Sunday of March, clocks jump from 1:59 a.m. straight to 3:00 a.m. — the 2 a.m. hour does not exist, and that day is 23 hours long. On the first Sunday of November, clocks go from 1:59 a.m. back to 1:00 a.m., so the 1 a.m. hour happens twice and that day runs 25 hours. That repeated hour is why scheduled jobs around 1–2 a.m. should run on UTC, not local time.
Do Europe and the US change clocks on the same dates?
No. The EU switches on the last Sunday of March and the last Sunday of October, at 1:00 a.m. UTC — in 2026, March 29 and October 25. The US uses the second Sunday of March and the first Sunday of November. During the mismatch, the usual 5-hour New York–London gap shrinks to 4: about three weeks each spring and one week each fall. Recurring transatlantic meetings shift by an hour in those windows.
Is Puerto Rico on EST or EDT?
Neither. Puerto Rico uses Atlantic Standard Time, UTC-4, all year, and never changes its clocks — as is true of the other US territories, Hawaii, and Arizona outside the Navajo Nation. In summer, Puerto Rico's clocks happen to match New York's, since EDT is also UTC-4; in winter, Puerto Rico runs an hour ahead. Matching offset, different zone — one more reason to convert by date rather than by abbreviation.
Need one specific time converted? The UTC to EST converter applies the correct EST or EDT offset for any date.
Open UTC to EST Converter →