WorldClockTools.

IANA timezone

America/Adak.

HADTUTC-09:00Observing DST

America/Adak is the IANA timezone for United States, currently at UTC-09:00 (HADT). It observes daylight saving time, so the offset changes on the scheduled transition dates each year. The zone covers 1 city listed below, with live clocks updating every second.

Offset, DST behavior, and city coverage are refreshed from the live timezone dataset during the page revalidation window.

Current time in HADT

--:--:--

America/Adak · UTC-09:00

All timezones in United States →View HADT abbreviation →

Abbreviation

HADT

UTC Offset

UTC-09:00

DST Status

Observing DST

Country

United States

Timezone planning depth

What America/Adak is useful for

A timezone page should do more than define an offset. These notes connect the zone to city clocks, DST behavior, converters, and adjacent country planning pages.

Zone identity

America/Adak is rendered as HADT at UTC-09:00 for United States. The IANA zone ID is the stable key; the abbreviation is only the short display label.

DST behavior

America/Adak has 1 scheduled offset transition in the next 12 months. Next transition: March 14, 2027 (UTC-10:00 → UTC-09:00, +1h). Cumulative offset movement across the window is +1h. Use the IANA zone ID rather than a fixed UTC offset when scheduling across these dates.

City coverage

1 indexable city sits in this zone after locale and crawl-safety filters, with Adak among the examples shown.

Conversion handoff

HADT has no pre-built converter pair, so a custom comparison runs through the general timezone converter instead.

Adjacent planning context

The most useful next steps from this timezone page are holiday calendars, airport-country planning, and city clocks. Those links keep the zone page connected to real user tasks rather than stopping at an offset definition.

Abbreviations across the year

America/Adak resolves to multiple display abbreviations in the next 12 months: HADT and HAST. The abbreviation rotates with the offset, which is why long-lived calendar entries should be anchored to the IANA zone instead of a saved abbreviation.

Offset stability

America/Adak spends about 236 days at UTC-09:00 across the forward 12-month window, which makes it the longer-running of two seasonal offsets. The remaining time is split across the other offsets listed in the year-of-DST card.

Peer zones at the same offset

Other IANA zones currently aligned at UTC-09:00 include Pacific/Rarotonga, Pacific/Honolulu, and Pacific/Tahiti. Same-offset peers can drift apart later in the year if their DST rules differ, so a peer match today is not a permanent equivalence.

Country roster

America/Adak is used as the primary clock anchor for United States. The roster is derived from country-zone mappings, so it reflects which jurisdictions adopt this IANA zone rather than which countries happen to share its current offset.
Timezone abbreviations can be ambiguous. The IANA zone name is the canonical key used for clocks, city pages, and conversion math.

Source-change watch

When timezone policy changes

Machine-readable rule source

Exact offsets and transition rows come from the IANA Time Zone Database as exposed by the deployed runtime. IANA publishes tzdb releases when governments change civil-time rules.

Check IANA Time Zone Database

Policy-source boundary

No jurisdiction-specific policy source is attached for America/Adak. Confirm legal clock-change announcements with the relevant government or time authority before relying on future rules.

Year-round offset behavior

America/Adak across the next 12 months

The forward 12-month sweep returned 1 scheduled offset transition. Cumulative offset movement is +1h. Anchor stored timestamps to the IANA zone, not to a fixed UTC offset.

Date (local)Local timeFromToGap
March 14, 20273:00 AMUTC-10:00 (HAST)UTC-09:00 (HADT)+1h

Offset window

UTC-10:00 (HAST)

129 days

Offset window

UTC-09:00 (HADT)

236 days

Primary offset across the window: UTC-09:00 (HADT) for about 236 days.

Coverage reference

What America/Adak covers

Country roster

United States

Common abbreviations

HADTHAST

Abbreviations rotate with each DST transition — anchor calendar entries to the IANA zone, not an abbreviation.

Peer zones at UTC-10:00 right now

Pacific/RarotongaPacific/HonoluluPacific/Tahiti

Same-offset peers can drift apart later in the year if their DST rules differ; today's offset match is not a permanent equivalence.

Top cities in America/Adak (by population)

Adak

DST mismatch radar

Meetings drift when regions change their clocks on different weekends. Dates below are computed from the IANA time zone rules as of 5 Nov 2026.

Upcoming DST shifts

  • United States and Canada
    Clocks go forward 1 hour · UTC-05:00 → UTC-04:00
    Sun 14 Mar 2027
  • UK and European Union
    Clocks go forward 1 hour · UTC+00:00 → UTC+01:00
    Sun 28 Mar 2027
  • New Zealand
    Clocks go back 1 hour · UTC+13:00 → UTC+12:00
    Sun 4 Apr 2027
  • South-east Australia
    Clocks go back 1 hour · UTC+11:00 → UTC+10:00
    Sun 4 Apr 2027

Meetings at risk

  • New York ↔ London
    • Sun 14 Mar 2027 (New York changes)5 h → 4 h
    • Sun 28 Mar 2027 (London changes)4 h → 5 h
    • Sun 31 Oct 2027 (London changes)5 h → 4 h
    • Sun 7 Nov 2027 (New York changes)4 h → 5 h

    4 h instead of 5 h for 14 days, Sun 14 Mar 2027 to Sun 28 Mar 2027.

    4 h instead of 5 h for 7 days, Sun 31 Oct 2027 to Sun 7 Nov 2027.

  • New York ↔ Sydney
    • Sun 14 Mar 2027 (New York changes)16 h → 15 h
    • Sun 4 Apr 2027 (Sydney changes)15 h → 14 h
    • Sun 3 Oct 2027 (Sydney changes)14 h → 15 h
    • Sun 7 Nov 2027 (New York changes)15 h → 16 h
  • London ↔ Sydney
    • Sun 28 Mar 2027 (London changes)11 h → 10 h
    • Sun 4 Apr 2027 (Sydney changes)10 h → 9 h
    • Sun 3 Oct 2027 (Sydney changes)9 h → 10 h
    • Sun 31 Oct 2027 (London changes)10 h → 11 h

Each gap is how many hours the second city is ahead of the first.

Holidays in United StatesAirports in United States

Cities in HADT

Adak

FAQ

What is the current UTC offset for America/Adak?
America/Adak is currently at UTC-10:00 (HAST). The page revalidates weekly, but live clocks on this page tick from the IANA zone in real time.
Does America/Adak observe daylight saving time in 2027?
Yes. America/Adak has 1 scheduled transition in the next 12 months. The first is March 14, 2027 (UTC-10:00 → UTC-09:00, +1h). Anchor saved timestamps to the IANA zone, not to a fixed UTC offset, so they survive the change automatically.
Which cities use America/Adak?
America/Adak is the canonical clock for cities including Adak. The page lists 1 indexable city in this zone after locale and crawl-safety filters.
What abbreviations does America/Adak use?
America/Adak resolves to HADT, HAST across the next 12 months — the abbreviation rotates with each DST transition. Calendar entries should anchor to the IANA zone instead of an abbreviation so the right offset is used in each window.
Why does United States use America/Adak?
United States is mapped to America/Adak as one of its IANA zones in the country-zone catalog. The IANA zone records each jurisdiction's historical offset and DST rule changes; America/Adak stores the rules used by United States (ISO US).

Related timezone pages

Most timezone-reference visits naturally branch into a country page, abbreviation page, or converter workflow.

Time in United States

Open the country hub for city clocks, holidays, airports, and broader timezone context.

Timezone converter

Move from zone reference into hour-by-hour practical conversions.

Browse city pages

Use the human-readable city index if the next question is really about a city, not a zone string.