Skip to content
Open the map

America/Adak

America/Adak is the IANA time zone for Alaska – western Aleutians in the United States.

UTC−09:00

Mon, Sep 28 UTC−9 HADT

Offsets and daylight saving time

Standard offset
UTC−10:00
Daylight offset
UTC−09:00
Rule
Daylight saving time from the second Sunday in March at 02:00 to the first Sunday in November at 02:00 (local time).

Next clock changes

  • Sunday, November 1, 2026 at 02:00: back to UTC−10 (HADT → HAST)
  • Sunday, March 14, 2027 at 02:00: forward to UTC−9 (HAST → HADT)

Names

Generic name
Hawaii-Aleutian Time
Abbreviation
HAST / HADT
Standard / daylight
Hawaii-Aleutian Standard Time / Hawaii-Aleutian Daylight Time
Aliases
America/Atka and US/Aleutian (old ids that resolve to America/Adak)

Use it in code

// JavaScript
new Intl.DateTimeFormat('en-US', { timeZone: 'America/Adak' })

# Python
from zoneinfo import ZoneInfo
ZoneInfo('America/Adak')

-- PostgreSQL
SELECT now() AT TIME ZONE 'America/Adak';

Offset history since 1970

  • 1970–1983: UTC−11 and UTC−10 each year
  • 1984–2026: UTC−10 and UTC−9 each year

Open in the map →