Basics · Standard time

EST: Eastern Standard Time

EST is UTC−5, five hours behind Coordinated Universal Time. It is the standard time of the Eastern Time Zone, kept from 2:00 AM on the first Sunday in November until 2:00 AM on the second Sunday in March.

UTC offset
−05:00
Now in effect
EST or EDT
Season
Nov → Mar
Reference meridian
75°W

When is Eastern Standard Time in effect?

EST begins when clocks fall back from 2:00 AM EDT to 1:00 AM EST on the first Sunday in November (06:00 UTC) and ends when they spring forward from 2:00 AM EST to 3:00 AM EDT on the second Sunday in March (07:00 UTC). At this moment the zone is on EST or EDT; the live Eastern Time clock shows the exact time.

EST seasons in the Eastern Time Zone, 2025–2030
WinterEST beginsEST endsDays
2025–26Sunday, November 2, 2025Sunday, March 8, 2026126
2026–27Sunday, November 1, 2026Sunday, March 14, 2027133
2027–28Sunday, November 7, 2027Sunday, March 12, 2028126
2028–29Sunday, November 5, 2028Sunday, March 11, 2029126
2029–30Sunday, November 4, 2029Sunday, March 10, 2030126

That makes EST the shorter of the two settings, a little over a third of the year. How it stacks up against the 34-week daylight season, and which label to write when, is covered in EST vs EDT.

Why is EST five hours behind UTC?

The Earth turns 360° in 24 hours, or 15° per hour. Standard time zones were laid out so that each keeps the mean solar time of a meridian that is a multiple of 15° from Greenwich. Eastern Standard Time belongs to the 75th meridian west: 75 ÷ 15 = 5, so EST runs five hours behind Greenwich and, today, behind UTC. The 75°W line passes just east of Philadelphia, where mean solar noon falls within a minute of 12:00 PM EST.

Everywhere else in the zone the sun is early or late by 4 minutes for every degree of longitude. Boston, about 4° east of the meridian, reaches mean noon 16 minutes before the clock does; Detroit, 8° west, about 32 minutes after; and Indianapolis, at 86°W and well outside the ideal 15° band, about 45 minutes after. That is why winter mornings stay dark so long in Indiana and Michigan. The real boundary was drawn around railroad division points and county lines rather than meridians, a story told on the time zone boundaries page.

Longitude and solar time: the 75th meridian west defines EST; cities east of it see mean solar noon before 12:00 PM EST, cities west of it after 90°W · CST meridian75°W · EST meridian (UTC−5)ideal band 82.5°W–67.5°W85°W80°W75°W70°W1° of longitude = 4 minutes of solar time · 15° = 1 hour Indianapolis−45 minDetroit−32 minWashington−8 minNew York+4 minAtlanta−38 minMiami−21 minPhiladelphia−1 minBoston+16 min
Local mean time minus EST, from each city's longitude. True solar noon also drifts up to about a quarter of an hour over the year.

What does US law say about Eastern Standard Time?

Federal law divides the United States into nine standard-time zones. Under 15 U.S.C. §261(a) the Eastern zone is the second of them (Atlantic is the first), and its standard time is "Coordinated Universal Time retarded by 5 hours". Section 263 gives it its legal name, "eastern standard time". Until 2007 the statute tied the zone to "the seventy-fifth degree" of longitude west of Greenwich; the America COMPETES Act (Public Law 110–69) replaced that solar definition with UTC in August 2007. Clocks did not move: mean solar time at 75°W and UTC−5 never differ by more than about a second.

Where the zone applies is decided by the Secretary of Transportation, who must have regard for "the convenience of commerce". The result is 49 CFR Part 71: §71.4 begins "The second zone, the eastern standard time zone, includes that part of the United States…", and §71.5 traces the boundary with the Central zone. Daylight saving time is layered on top in §71.2, which says standard time "shall be advanced 1 hour" from the second Sunday in March to the first Sunday in November; that advanced time is EDT. In Canada, time is set by each province, in Ontario's case by its Time Act.

Where is it EST all year?

Several places sit on UTC−5 and never switch to daylight time. For about four months a year they share New York's clock, and for the other eight they are an hour behind it. The tz database labels all of them EST:

Places that keep EST (UTC−5) without daylight saving
PlaceIANA zoneOn EST all year since
PanamaAmerica/Panama1908, when it left Colón Mean Time
JamaicaAmerica/Jamaica1984, after following US daylight saving from 1974 to 1983
Cayman IslandsAmerica/Caymanat least 1970
Quintana Roo, Mexico (Cancún)America/CancunFebruary 1, 2015
Atikokan, OntarioAmerica/Atikokanat least 1952
Southampton Island (Coral Harbour), NunavutAmerica/Coral_Harbourdecades; the start date is not documented

Since November 1, 2026, Manitoba has joined them in practice. The province stopped changing clocks and now keeps UTC−5 all year, which it calls Manitoba Standard Time, and Ontario moved its territory west of 90°W, including Kenora and Fort Frances, to UTC−5 year-round on the same day. Locally this is described as permanent daylight time, but on the clock it is identical to EST, so Winnipeg and Toronto now agree every winter. Colombia, Ecuador and Peru are UTC−5 all year too, under their own national names; the full list is on everywhere at UTC−5.

Why is "EST" so often used incorrectly?

Many writers use EST to mean "Eastern Time" all year. Human readers usually translate without noticing, so during the 34 weeks of EDT the mistake mostly stays on paper. The real damage happens in systems, because EST is a fixed offset and they take it literally.

The tz database entry named EST is a fixed UTC−5 zone with no daylight saving, today an alias of America/Panama, so a server or calendar set to "EST" instead of America/New_York runs an hour off from March to November. On a Unix system, TZ=EST prints a July evening as EST while New York clocks show EDT.

The fix is simple: keep EST for dates between November and March, use EDT for the rest, and write ET when no date is attached. The UTC offset guide shows how to store times so that the label never matters, and the season-by-season rules for the switch are in the daylight saving time guide.

Frequently asked questions

Is EST the same as Central Daylight Time?

On the clock, yes: both are UTC−5. From March to November, Chicago on CDT shows the same time as Panama or Jamaica on EST, and the same time New York would show if it stayed on standard time.

Does EST change for daylight saving time?

No. EST itself is a fixed offset, UTC−5, and never moves. What changes is the zone: in March the Eastern Time Zone leaves EST for EDT, and in November it returns.

What is 12:00 PM EST in Central, Mountain and Pacific time?

11:00 AM CST, 10:00 AM MST and 9:00 AM PST. The gaps are the same all year because those zones change clocks on the same Sundays; Arizona, which stays on MST, also shows 10:00 AM in winter.

What time did the East use before EST?

Local mean time. Each city set its clocks by its own sun: the tz database records New York's local time as 4 hours 56 minutes 2 seconds behind Greenwich and Toronto's as 5 hours 17 minutes 32 seconds. Railroads switched to standard zones on November 18, 1883, and Congress wrote them into law in 1918.

Explore

EST vs EDT

The side-by-side comparison, which one is in force now and when to write ET.

EDT explained

UTC−4 from March to November, the 2027 season and what it does to sunsets.

Everywhere at UTC−5

Every country and territory that shares EST's offset, with or without daylight saving.