Current Time in US/Aleutian Time Zone

Where Does US/Aleutian Apply?

The US/Aleutian zone applies to the Aleutian Islands, a chain of volcanic islands extending westward from the Alaska Peninsula. The primary inhabited islands include Unalaska (Dutch Harbor), Adak, Atka, and Shemya. The zone is used by the communities and military installations in this remote region. Note that the rest of Alaska uses Alaska Time (UTC-9:00/UTC-8:00), so the Aleutian Islands are one hour behind mainland Alaska during standard time.

Offset and Abbreviation

Standard time in US/Aleutian is Hawaii-Aleutian Standard Time (HST), which is UTC-10:00. During daylight saving time, clocks advance to Hawaii-Aleutian Daylight Time (HDT), UTC-09:00. The abbreviation HST is shared with Hawaii, but Hawaii does not observe DST, so while Hawaii stays on HST year-round, the Aleutian Islands switch to HDT in summer.

Daylight Saving Time Behavior

US/Aleutian observes daylight saving time, following the same schedule as the rest of the United States. Clocks spring forward on the second Sunday of March and fall back on the first Sunday of November. Upcoming changes: March 9, 2025 (to HDT), November 2, 2025 (to HST), March 8, 2026 (to HDT), November 1, 2026 (to HST). The shift means that during summer, the Aleutian Islands are only 9 hours behind UTC, aligning with Hawaii's standard time offset (but Hawaii does not change). This creates a temporary one-hour difference between the Aleutians and Hawaii during DST.

Main Locations and Users

The largest settlement in the zone is Unalaska, home to the Port of Dutch Harbor, a major fishing port. Adak, Atka, and Nikolski are other communities. The zone is also used by the US military at Shemya Air Force Base (Eareckson Air Station). The population is small, but the zone is critical for maritime and aviation operations in the North Pacific.

Business Hours and Scheduling

US/Aleutian is 10 hours behind UTC. When scheduling calls with the US mainland, note that the Aleutians are one hour behind Alaska (Anchorage) and four hours behind New York (Eastern Time) during standard time. During DST, the difference with Eastern is 5 hours (since Eastern also observes DST). For example, 9 AM in New York is 4 AM in the Aleutians during standard time and 5 AM during DST. For calls with Asia, the offset is convenient: Tokyo (UTC+9) is 19 hours ahead in standard time, meaning 10 AM in Unalaska is 5 AM the next day in Tokyo. With Hawaii, the Aleutians share the same time during standard time but are one hour ahead during DST (since Hawaii does not observe DST).

Comparison with Other Zones at UTC-10

Other IANA zones at UTC-10 include America/Adak (also Aleutian Islands but a different zone name), Pacific/Honolulu (Hawaii, no DST), Pacific/Rarotonga (Cook Islands, no DST), Pacific/Tahiti (French Polynesia, no DST), and US/Hawaii (same as Pacific/Honolulu). The key difference is DST observance: only the Aleutian zones (US/Aleutian and America/Adak) change clocks; the others remain on standard time year-round.