| Atlantic Time Zone | |
|---|---|
| Time zone | |
 Atlantic Time Zone | |
| UTC offset | |
| AST | UTC−04:00 |
| ADT | UTC−03:00 |
| Current time | |
| 15:42, 14 February 2026AST[refresh] | |
| Observance ofDST | |
| DST is observed in parts of this time zone. | |
TheAtlantic Time Zone is a geographical region that keeps standard time—calledAtlantic Standard Time (AST)—by subtracting four hours from Coordinated Universal Time (UTC), resulting inUTC−04:00. AST is observed in parts of North America including several Caribbean islands. During part of the year, some portions of the zone observedaylight saving time, referred to asAtlantic Daylight Time (ADT), by moving their clocks forward one hour toUTC−03:00. The clock time in this zone is based on themean solar time of the60th meridian west of theGreenwich Observatory.
In Canada, the provinces ofNew Brunswick,[1]Nova Scotia,[2] andPrince 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 ofQuebec (easternCôte-Nord and theMagdalen Islands) also observe Atlantic Time. Officially, the entirety ofNewfoundland and Labrador observesNewfoundland Standard Time,[3] but in practice Atlantic Time is used in most ofLabrador.
No part of thecontinental United States uses Atlantic Time, although it is used by the territories ofPuerto Rico and theU.S. Virgin Islands. In the 2010s, several U.S. states considered legislation to move from the Eastern Time Zone to Atlantic Standard Time. Any changes must be approved by theUnited States Department of Transportation and theUnited States Congress before taking effect.
The United StatesNational 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 toEastern Daylight Time (EDT) for most of the Atlantic hurricane season).[4]
All six of theNew 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 ofMaine lies east of that meridian. AMassachusetts 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.[5] In May 2017, theMaine Senate approved a change to AST, on the condition that there would be a referendum, and that Massachusetts andNew Hampshire must make the same switch.[6] Also in 2017, theNew Hampshire House of Representatives approved a bill in favor of a regional change, but this was voted down by thestate's Senate.[7] Similar bills have been put forward inConnecticut,Rhode Island, andVermont.[6][8]
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'spanhandle region would move to year-roundCentral Daylight Time.[9][10] However, the change cannot take effect until it is passed into federal law by theUnited States Congress.[10]
On March 15, 2022, theUnited States Senate voted unanimously to advance a federal version of the "Sunshine Protection" legislation from Florida, also called the "Sunshine Protection Act", to theUnited States House of Representatives;[11] the bill was not brought to a vote in the House.[12] A similar bill was introduced in the Senate in 2023.[13]
In Vermont, Democrat Rep. Samuel Young this year has submitted legislation that would establish year-round Eastern daylight saving time.
