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Time in Guam — regions, cities and time zones

Guam runs on Chamorro Standard Time, UTC+10:00, throughout the year with no daylight saving. The territory sits far west in the Pacific, which puts its calendar date ahead of the United States mainland by a full day for much of each day.

Flag of Guam Guam

Capital Hagåtña · Oceania · ISO GU / GUM

Hagåtña, Guam

Saturday, 5 September 2026

UTC+10 · Pacific/Guam

Time and sun data for Hagåtña, Guam

The sun in Hagåtña

Sunrise 6:11 AM Solar noon 12:21 PM Sunset 6:32 PM Daylight 12 h 20 min Night 11 h 40 min Civil twilight 5:50 AM – 6:53 PM

States and regions (19)

Current time in Hagåtña

Hagåtña, the capital on the island's western coast, keeps the same clock as Dededo, Tamuning and every other village on Guam. The island is roughly fifty kilometres long and entirely on one offset — there is nothing regional to reconcile.

The zone name is worth knowing because it is specific to this part of the Pacific: Chamorro Standard Time, named for the indigenous people of the Marianas, covers Guam and the Northern Mariana Islands together.

"Where America's day begins"

Guam's position gives it one of the earliest clocks under the US flag, and the phrase is used locally with some pride. Practically, it creates a date gap that catches out anyone coordinating with Washington or the West Coast:

For a large part of the day, Guam is on tomorrow's date relative to the US mainland. A Monday morning meeting on Guam is a Sunday event for much of America. Deadlines expressed in mainland time can fall on what is locally the following day.

On Guam, "I'll get to it tomorrow" is technically an offer to do it before the mainland has finished today.

No clock changes, ever

Guam does not observe daylight saving time. Like other US territories in the tropics, it stays on a single offset year-round. Being close to the equator, the island sees very little seasonal swing in day length, so shifting the clock would gain nothing.

Since the mainland United States does change clocks, the difference between Guam and American cities moves twice a year — through no action on Guam's part. Standing calls with the mainland need rechecking after each US transition.

Neighbours in the region

Guam shares its offset with several Pacific and Asian locations, which makes regional coordination straightforward: The Northern Mariana Islands, immediately to the north, are on the same clock. Papua New Guinea and parts of eastern Australia sit on the same offset, though Australian daylight saving complicates the southern states seasonally. Tokyo and Seoul are an hour behind Guam, not ahead — a common mix-up.

Questions and answers
What time zone is Guam in?
Chamorro Standard Time, UTC+10:00, across the whole territory.
Does Guam use daylight saving time?
No. The offset stays the same all year.
Why is Guam a day ahead of the United States?
Guam lies west of the International Date Line relative to the US mainland, so for much of each day its calendar date is one day further on.

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