When to phone Northern Mariana Islands (+1-670)
The CNMI runs on Chamorro Standard Time — UTC+10 year-round. Tourism and defense contacts on Saipan are reachable 8 AM–5 PM ChST.
ChST (UTC+10), at a glance.
The Northern Mariana Islands observes Chamorro Standard Time at UTC+10 all year with no daylight saving. Saipan, Tinian and Rota share UTC+10.
CNMI against the world's hubs.
Saipan is 10 h ahead of London, 2 h ahead of Tokyo and 15 h ahead of New York. Tokyo callers reach Saipan from 10 AM JST; LA callers must dial in the evening.
Understanding the time difference between the United States and Northern Mariana Islands
Time zone differences across other major countries
Why timing matters for calls to the CNMI.
Tourism operators and defense procurement contacts on Saipan keep standard hours. The 8–10 AM ChST window catches them before midday and aligns with Tokyo's early afternoon for Japan-market resort bookings.
The best windows to reach the Northern Mariana Islands.
8 AM–11 AM ChST for tourism and logistics; defense contractor contacts on Tinian often start at 7 AM. From Tokyo, that's 9 AM–12 PM — a clean overlap.
Northern Mariana Islands runs at +10:00
The zone is Pacific/Saipan. Every window on this page is worked out from that offset rather than a rule of thumb, so the times shown are the ones that actually apply to Northern Mariana Islands.
No daylight saving
Northern Mariana Islands stays on +10:00 all year. The windows below only move when the caller's own country changes its clocks, not when Northern Mariana Islands does.
Shared hours with 2 of 5 markets
Callers in Mumbai, Sydney share part of the working day with Northern Mariana Islands. The table above gives the exact intersection for each.
Where the gap is too wide
There is no 9-to-5 overlap with New York, Los Angeles, London. Calling Northern Mariana Islands from those cities means someone is working outside normal hours — worth saying so when you book the call.
How to call the Northern Mariana Islands using the +1-670 code.
Dial +1-670 then the seven-digit local number. Ringflow's NANP routing connects to Saipan on Pacific DID infrastructure.
Number anatomy
Dial exit code
Press + on mobile or 00 from most landlines. This opens an international line.
Enter +1-670
Northern Mariana Islands's international code. Every call to Northern Mariana Islands must start with +1-670.
Area prefix
Add the local area or mobile network code — always drop any leading zero used for domestic calls.
Full number
Dial the remaining subscriber digits. Your number is now correctly formatted for international routing.
Best time to call — every country.
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Reach Northern Mariana Islands contacts in their window, on the right network.
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When your working day overlaps Northern Mariana Islands
Callers in Mumbai and Sydney share part of the working day with Northern Mariana Islands. There is no shared working window with New York, Los Angeles and London.
| Calling from | Northern Mariana Islands is | Call at (your time) | Which is (their time) |
|---|---|---|---|
| New York | 15h ahead | No shared working hours — you would need to call outside 9am-5pm | |
| Los Angeles | 18h ahead | No shared working hours — you would need to call outside 9am-5pm | |
| London | 10h ahead | No shared working hours — you would need to call outside 9am-5pm | |
| Mumbai | 4h 30m ahead | 9:00 AM – 12:30 PM | 1:30 PM – 5:00 PM |
| Sydney | 1h behind | 10:00 AM – 5:00 PM | 9:00 AM – 4:00 PM |
Windows are the intersection of a 9am-5pm working day in each place, using Northern Mariana Islands'standard-time offset of +10:00. Northern Mariana Islands does not observe daylight saving, so these windows hold all year — though they shift when the caller's own country changes its clocks.
FAQ
Calling Northern Mariana Islands, answered.
Time zone, daylight saving and dialling questions for Northern Mariana Islands (+1-670).