Timezone abbreviation
ADT currently resolves here through America/Halifax, where the live offset is -03:00 (ADT). This page expands that into the broader meaning set, top cities, countries, similar labels, and safer exact-zone equivalents.
Last updated Apr 26, 2026. Representative zones, offset ranges, and city usage are refreshed from the current timezone dataset so abbreviation pages stay tied to real zones instead of static boilerplate.
ADT is a North or South American civil-time label, currently 3h behind UTC at -03:00. The label covers 3 IANA zones across 3 countries, with Halifax as the busiest live reference.
The busiest cities using ADT in the current catalog are Halifax, Dartmouth, Lower Sackville, Charlottetown, and Downtown Halifax. The lead live reference on this page is Halifax (America/Halifax), currently at -03:00 (ADT). Those cities are what give ADT its actual feel rather than the abstract offset.
ADT currently shows -03:00, but America/Halifax observes seasonal clock changes — the next transition is around November 1, 2026. That means the offset on this page is a snapshot, not a permanent fact, so long-range scheduling should pin the underlying IANA zone instead of the abbreviation.
Live reference
America/Halifax
Current offset
-03:00 (ADT)
Meanings / zones / countries
1 / 3 / 3
Offset range
UTC-04:00 to UTC-03:00
ADT is slightly behind UTC, which keeps it within a normal trans-Atlantic working pair. In practice it is read inside North America, where the leading city anchors are Halifax, Canada, Dartmouth, Canada, and Lower Sackville, Canada.
ADT resolves cleanly in the current dataset, with one dominant meaning across 3 zones and 3 country groups.
ADT shows up on broadcast guides, sports schedules, and inter-state corporate calendars. ADT can also flip to a sibling daylight-saving abbreviation later in the year, so timestamps before and after the change need to be read carefully.
Canada sits in Americas, specifically North America. Population 41,651,653, area 9,984,670 km², capital Ottawa. Civic markers behind ADT include English and French and CAD (Canadian dollar, $).
Halifax is the clearest city-level anchor: Halifax commonly refers to:Halifax, Nova Scotia, Canada Halifax, West Yorkshire, England Halifax (bank), a British bank
ADT in the Atlantic Time meaning runs 3h behind UTC through North America, threading zones such as America/Halifax, Atlantic/Bermuda, and America/Thule (cities: Halifax, Dartmouth, and Lower Sackville). Country anchors: Canada, Bermuda, and Greenland.
Atlantic Time
Current reading: ADT at -03:00 in Canada.
America/Halifax changes on November 1, 2026 at about 1:10 AM, moving from AST (-04:00) to AST (-04:00).
City anchors include Halifax, Dartmouth, and Lower Sackville, while country anchors include Canada, Bermuda, and Greenland.
Atlantic Time
Current reading: ADT at -03:00 in Bermuda.
Atlantic/Bermuda changes on November 1, 2026 at about 1:10 AM, moving from AST (-04:00) to AST (-04:00).
City anchors include Halifax, Dartmouth, and Lower Sackville, while country anchors include Canada, Bermuda, and Greenland.
Atlantic Time
Current reading: ADT at -03:00 in Greenland.
America/Thule changes on November 1, 2026 at about 1:10 AM, moving from AST (-04:00) to AST (-04:00).
City anchors include Halifax, Dartmouth, and Lower Sackville, while country anchors include Canada, Bermuda, and Greenland.
Live reference zone: America/Halifax (ADT, -03:00)
Leading city in the current dataset: Halifax, Canada.
Cities: Halifax, Canada, Dartmouth, Canada, and Lower Sackville, Canada. Countries: Canada, Bermuda, and Greenland.
Live zones: America/Halifax (-03:00), Atlantic/Bermuda (-03:00), and America/Thule (-03:00).
Countries
Canada, Bermuda, Greenland
Top cities
Halifax, Dartmouth, Lower Sackville, Charlottetown
Canada runs on a single zone (13 mapped cities) under ADT. Visible cities: Halifax, Dartmouth, and Lower Sackville. Underlying zones: America/Halifax.
Bermuda runs on a single zone (1 mapped cities) under ADT. Visible cities: Hamilton. Underlying zones: Atlantic/Bermuda.
Greenland runs on a single zone (0 mapped cities) under ADT. Visible cities: the lead reference city. Underlying zones: America/Thule.
City anchors for ADT (North America, currently -03:00). Pick a city to drop into a live local clock.
Canada
Cities: Halifax, Dartmouth, Lower Sackville, Charlottetown
Meaning group: Atlantic Time
Bermuda
Cities: Hamilton
Meaning group: Atlantic Time
Greenland
Zones: America/Thule
Meaning group: Atlantic Time
ADT reads cleanly across the Americas in this dataset, but the same letters can mean different things elsewhere (notably CST, EST, and IST overlap with non-American labels). Pin the IANA zone when the audience is international.
America/Halifax has an upcoming offset change on November 1, 2026. After that point, ADT on this page will read a different UTC offset until the next transition, so any saved timestamp should anchor to the IANA zone rather than the abbreviation.
For precise work, the safest equivalent of ADT is the exact IANA zone used by your city or system. America/Halifax sits at -03:00, behind UTC, which means daily logs in this zone reach a new calendar date after UTC does — relevant for date-aligned reports and billing cutoffs.
Even with one canonical meaning, ADT spans 3 IANA zones — pin to America/Halifax when DST or historical-rule precision matters.
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