{{Short description|Time zone in North America}} {{Use mdy dates|date=March 2026}} {{Infobox time zone |title = Atlantic Time Zone |image = North American Time Zones 2026.png |offset = −04:00 |dst offset = −03:00 |initials = AST |dst initials= ADT |dst use = parts |caption = {{legend|#dbde64|Atlantic Time Zone}}}} The '''Atlantic Time Zone''' is a geographical region that keeps standard time—called '''Atlantic Standard Time''' ('''AST''')—by subtracting four hours from Coordinated Universal Time (UTC), resulting in UTC−04:00. AST is observed in parts of North America including several Caribbean islands. During part of the year, some portions of the zone observe daylight saving time, referred to as '''Atlantic Daylight Time''' ('''ADT'''), by moving their clocks forward one hour to UTC−03:00. The clock time in this zone is based on the mean solar time of the 60th meridian west of the Greenwich Observatory.
In Canada, the provinces of New Brunswick,<ref>{{cite web |title=CHAPTER T-6 – Time Definition Act |url=http://www.gnb.ca/0062/pdf-acts/t-06.pdf |access-date=September 11, 2012 |archive-url=https://web.archive.org/web/20081207171756/http://www.gnb.ca/0062/PDF-acts/t-06.pdf |archive-date=December 7, 2008}}</ref> Nova Scotia,<ref>{{cite web |title=Time Definition Act |url=http://www.gov.ns.ca/legislature/legc/statutes/timedefn.htm |access-date=June 2, 2008 |archive-url=https://web.archive.org/web/20080605041507/http://www.gov.ns.ca/legislature/legc/statutes/timedefn.htm |archive-date= June 5, 2008 |url-status=live}}</ref> and Prince Edward Island are in this zone, though legally they calculate time specifically as an offset of four hours from Greenwich Mean Time (GMT–4) rather than from UTC. Small portions of Quebec (eastern Côte-Nord and the Magdalen Islands) also observe Atlantic Time. Officially, the entirety of Newfoundland and Labrador observes Newfoundland Standard Time,<ref>{{cite web |title=RSNL1990 CHAPTER S-23 – STANDARD TIME ACT |url=http://www.assembly.nl.ca/legislation/sr/statutes/s23.htm |access-date=November 16, 2007}}</ref> but in practice Atlantic Time is used in most of Labrador.
No part of the continental United States uses Atlantic Time, although it is used by the territories of Puerto Rico and the U.S. Virgin Islands. In the 2010s, several U.S. states considered legislation to move from the Eastern Time Zone to Atlantic Standard Time. In 2026, a bill to move Georgia to AST was proposed.<ref>{{cite web |title=Georgia Senate advances bill that would switch Georgia's time zone, end twice-annual time change |url=https://www.wabe.org/a-new-bill-would-switch-georgias-time-zone-and-move-the-state-to-year-round-daylight-saving-time/ |access-date=March 23, 2026}}</ref> Any changes must be approved by the United States Department of Transportation and the United States Congress before taking effect.
The United States National Hurricane Center's official advisories typically report AST and UTC when tracking storms in the Caribbean that threaten the U.S., which may confuse the mainland public not familiar with the time zone designation (although AST is equivalent to Eastern Daylight Time (EDT) for most of the Atlantic hurricane season).<ref>{{cite web|url=https://www.nhc.noaa.gov/|title=Advisories|website=National Hurricane Center}}</ref>
==Areas covered== ===Caribbean=== {{div col}} *Antigua and Barbuda *Barbados *Dominica *Dominican Republic *France and French overseas collectivities, in the following areas: **Guadeloupe **Martinique **Saint Barthélemy **Saint-Martin *Grenada *Former Netherlands Antilles and Dutch special municipalities, in the following areas: **Aruba **Bonaire **Curaçao **Saba **Sint Eustatius **Sint Maarten *Saint Kitts and Nevis *Saint Lucia *Saint Vincent and the Grenadines *Trinidad and Tobago *United Kingdom (British Overseas Territories), in the following areas: **Anguilla **British Virgin Islands **Montserrat *United States territories, in the following areas: **Puerto Rico **United States Virgin Islands {{div col end}}
===North America=== *Canada, in the following areas: **Nova Scotia **New Brunswick **Prince Edward Island **Most of Labrador **Magdalen Islands, Quebec **Côte-Nord (east of the 63rd meridian), Quebec (no DST)
===Additional local areas=== *Bermuda *Greenland, in the following area: **Pituffik Space Base
==U.S. states considering a change to Atlantic Standard Time==
All six of the New England states in the northeastern U.S., currently in the Eastern Time Zone (with daylight saving time), have considered legislation to shift to UTC−04:00, equivalent to Atlantic Standard Time (with no observance of daylight saving time) or Eastern Daylight Time. Virtually all of this region is west of the theoretical western border of the zone at 67.5°W; only a small part of Maine lies east of that meridian. A Massachusetts commission concluded in 2017 that the benefits of changing to Atlantic Standard Time year-round would outweigh the disadvantages, provided that a majority of northeastern states make the same change.<ref>{{cite news|title=Commission: Massachusetts Should Change Time Zones, But Not On Its Own|url=http://boston.cbslocal.com/2017/11/01/massachusetts-time-zone-change-daylight-saving/|access-date=March 15, 2018|date=November 1, 2017|language=en}}</ref> In May 2017, the Maine Senate approved a change to AST, on the condition that there would be a referendum, and that Massachusetts and New Hampshire must make the same switch.<ref name="timedatemaine">{{cite web|title=Maine Considers Atlantic Standard Time|url=https://www.timeanddate.com/news/time/maine-ast.html|website=www.timeanddate.com|access-date=March 15, 2018|language=en}}</ref> Also in 2017, the New Hampshire House of Representatives approved a bill in favor of a regional change, but this was voted down by the state's Senate.<ref>{{cite news|title=Senate votes down push to switch N.H.'s time zone|url=http://www.concordmonitor.com/time-zone-change-atlantic-9808198|access-date=March 15, 2018|date=May 11, 2017}}</ref> Similar bills have been put forward in Connecticut, Rhode Island, and Vermont.<ref name="timedatemaine" /><ref>{{Cite news|url=https://www.providencejournal.com/news/20190115/connecticut-bill-is-latest-calling-for-time-zone-change|title=Connecticut bill is latest calling for time zone change|last=Haigh|first=Susan|date=January 15, 2019|work=Providence Journal|access-date=September 10, 2019|quote=In Vermont, Democrat Rep. Samuel Young this year has submitted legislation that would establish year-round Eastern daylight saving time.}}</ref>
In 2018, Florida enacted into law the "Sunshine Protection Act", under which the state would observe daylight saving time year-round. Most of the state would permanently keep Eastern Daylight Time, which is equivalent to Atlantic Standard Time; the state's panhandle region would move to year-round Central Daylight Time.<ref>{{Cite web|url=https://www.miamiherald.com/news/state/florida/article196453714.html|title=Should Florida keep Daylight Saving Time all year? It could happen.|website=miamiherald|language=en|access-date=March 12, 2019}}</ref><ref name=":0">{{Cite news|url=https://www.orlandosentinel.com/news/politics/political-pulse/os-daylight-saving-law-20180703-story.html|title=Florida's year-round daylight saving time law on hold in Congress|last=Lemongello|first=Steven|website=OrlandoSentinel.com|language=en-US|access-date=March 12, 2019}}</ref> However, the change cannot take effect until it is passed into federal law by the United States Congress.<ref name=":0" />
On March 15, 2022, the United States Senate voted unanimously to advance a federal version of the "Sunshine Protection" legislation from Florida, also called the "Sunshine Protection Act", to the United States House of Representatives;<ref>{{Cite web |last=Palya |first=Ashley |date=March 15, 2022 |title=Turning Back Clocks A Thing Of The Past? Senate Passes Sunshine Protection Act |url=https://www.ibtimes.com/turning-back-clocks-thing-past-senate-passes-sunshine-protection-act-3438504 |access-date=March 17, 2022 |website=International Business Times}}</ref> the bill was not brought to a vote in the House.<ref>{{cite news |last1=Schnell |first1=Mychael |title=Permanent daylight saving time hits brick wall in House |url=https://thehill.com/homenews/house/3571007-permanent-daylight-saving-time-hits-brick-wall-in-house/ |work=The Hill |date=July 25, 2022}}</ref> A similar bill was introduced in the Senate in 2023.<ref>{{cite news |last1=Bink |first1=Addy |title=Daylight saving time: New bill could stop the clocks from changing |url=https://thehill.com/homenews/nexstar_media_wire/3880009-bill-to-make-daylight-saving-time-permanent-reintroduced-in-congress/ |work=The Hill |date=March 2, 2023}}</ref>
==See also== *Daylight saving time in the Americas
==References== {{Reflist}}
==External links== {{commons category}} * [https://time.is/AST Atlantic Standard Time: ''current time (live clock)''] * [https://time.is/ADT Atlantic Daylight Time: ''current time (live clock)''] * [https://nrc.canada.ca/en/web-clock/ Web clock (Official times across Canada)] * [https://www.worldtimezone.com/time-canada12.html Canada time zone map] {{North American time zones}} {{UTC time offsets}} {{authority control}}
Category:Time zones Category:Time zones in the United States