Five Inhabited Territories, Five Fixed Offsets
A call booked at 3 p.m. from New York to San Juan in July lands at the same hour. Book the same call in January and San Juan picks up at 4 p.m. The clock on the wall never moves in Puerto Rico, Guam, or American Samoa. The mainland does.
Every permanently inhabited US territory keeps a single UTC offset all year. No spring forward, no fall back. The mainland’s twice-yearly shift means the gap between, say, Chicago and Hagåtña shrinks by sixty minutes each March, then stretches again each November.
| Territory | Time Zone | UTC Offset | DST? |
|---|---|---|---|
| Puerto Rico | Atlantic Standard Time (AST) | UTC-4 | No |
| US Virgin Islands | Atlantic Standard Time (AST) | UTC-4 | No |
| Guam | Chamorro Standard Time (ChST) | UTC+10 | No |
| Northern Mariana Islands | Chamorro Standard Time (ChST) | UTC+10 | No |
| American Samoa | Samoa Standard Time (SST) | UTC-11 | No |
Puerto Rico and US Virgin Islands: Atlantic Standard Time
Puerto Rico and the US Virgin Islands (St. Thomas, St. John, St. Croix) share Atlantic Standard Time, UTC-4. San Juan and Charlotte Amalie run one hour ahead of Eastern Standard Time (EST, UTC-5) from November to March.
When the mainland shifts to Eastern Daylight Time (EDT, UTC-4) in March, the gap closes. From the second Sunday of March to the first Sunday of November, Puerto Rico and the East Coast show the same clock. A 3:00 p.m. call from New York lands at 3:00 p.m. in San Juan. From November to March, it lands at 4:00 p.m.
This seasonal flip is the most common source of scheduling errors. A habit formed in July (same time) is wrong in January (one hour ahead).
For live clocks, see Puerto Rico Time Now and U.S. Virgin Islands Time Now.
Guam and Northern Mariana Islands: Chamorro Standard Time
Guam and the Commonwealth of the Northern Mariana Islands (Saipan, Tinian, Rota) use Chamorro Standard Time, UTC+10. The zone is named for the indigenous Chamorro people of the Marianas.
ChST puts these Pacific outposts fifteen hours ahead of Eastern Standard Time. A Monday 9:00 a.m. in Hagåtña (Guam) is a Sunday 6:00 p.m. in New York during EST. During EDT, the gap is fourteen hours.
Guam sits west of the International Date Line. When it is 10:00 a.m. Wednesday in Washington D.C. (EDT), it is 12:00 a.m. Thursday in Guam. The islands are often described as where America’s day begins.
For the current time, see Guam Time Now and Northern Mariana Islands Time Now.
American Samoa: Samoa Standard Time
American Samoa uses Samoa Standard Time, UTC-11. Pago Pago is six hours behind Eastern Standard Time and one hour behind Hawaii (HST, UTC-10). During EDT, the gap to the East Coast is seven hours.
American Samoa is among the last inhabited places on Earth to see any given date end. When it is 11:00 p.m. Wednesday in Pago Pago, it is 5:00 a.m. Thursday in New York (EST).
The independent nation of Samoa, 160 kilometres away, moved to the west side of the International Date Line in 2011. The two Samoas are now roughly a day apart despite a short flight between them.
For the live clock, see American Samoa Time Now.
Do US Territories Observe Daylight Saving Time?
No. None of the five inhabited US territories observes daylight saving time.
- Puerto Rico: AST (UTC-4) year-round.
- US Virgin Islands: AST (UTC-4) year-round.
- Guam: ChST (UTC+10) year-round.
- Northern Mariana Islands: ChST (UTC+10) year-round.
- American Samoa: SST (UTC-11) year-round.
A fixed offset means the difference between a territory and a mainland state changes twice a year. A place that is one hour ahead of New York in January matches New York in July. A place that is fifteen hours ahead of New York in January is fourteen hours ahead in July.
For a full explanation of how the mainland zones shift, see US Time Zones Explained.
How Territory Times Compare to the Mainland US
Puerto Rico and US Virgin Islands (AST, UTC-4) - During EST (November to March): one hour ahead of Eastern Time, same as Eastern Daylight Time. - During EDT (March to November): same time as Eastern Time. - Two hours ahead of Central Time during CST, one hour ahead during CDT. - Four hours ahead of Pacific Time during PST, three hours ahead during PDT.
Guam and Northern Mariana Islands (ChST, UTC+10) - During EST: fifteen hours ahead of Eastern Time. - During EDT: fourteen hours ahead of Eastern Time. - During EST: eighteen hours ahead of Pacific Time. - During EST: twenty hours ahead of Hawaii.
American Samoa (SST, UTC-11) - During EST: six hours behind Eastern Time. - During EDT: seven hours behind Eastern Time. - One hour behind Hawaii year-round. - During EST: three hours behind Pacific Time.