ADT — Atlantic Daylight Time
ADT is Atlantic Daylight Time, -03:00, used in North America. In code, use America/Halifax rather than the abbreviation.
Atlantic Daylight Time · North America
21:15:39
Wednesday, 12 August 2026
- abbreviation denotes
- -03:00
- in force right now
- ADT (UTC-03:00) · DST
- use in code
- America/Halifax
- next clock change
- 1 Nov 2026 01:00 → AST
Use the IANA name, not the abbreviation
Python
from datetime import datetime
from zoneinfo import ZoneInfo
# right: an IANA zone carries the full history of rule changes
now = datetime.now(ZoneInfo("America/Halifax"))
print(now.isoformat(), now.tzname())
# wrong: an abbreviation is not resolvable, and a hard-coded offset
# silently rots the next time the rules change
# now = datetime.now(timezone(timedelta(hours=...))) # don'tADT questions
What does ADT stand for?
ADT is Atlantic Daylight Time, -03:00, used in North America. The IANA zone to use in code is America/Halifax.
What time is it in ADT right now?
Atlantic Daylight Time: 21:15 on Wednesday (ADT).
Which IANA timezone should I use instead of ADT?
America/Halifax for Atlantic Daylight Time. Date libraries cannot resolve bare abbreviations, and an abbreviation carries no daylight-saving history, so a stored offset silently rots when a government changes the rules.