Pacific/Guam is an IANA time zone used in Guam. It stays on UTC+10 all year.
Pacific/Guam at a glance
Rules of the Pacific/Guam time zone
No clock changes are scheduled in Pacific/Guam. The last one for daylight saving time was in 1977; since then the offset has been UTC+10 all year.
Recent and upcoming changes in Pacific/Guam
| Date | Change | New offset |
|---|---|---|
| Wednesday, May 26, 1976 | Clocks go forward 1 hour: 2:00 AM becomes 3:00 AM | UTC+11 |
| Sunday, August 22, 1976 | Clocks go back 1 hour: 2:01 AM becomes 1:01 AM | UTC+10 |
| Sunday, April 24, 1977 | Clocks go forward 1 hour: 2:00 AM becomes 3:00 AM | UTC+11 |
| Sunday, August 28, 1977 | Clocks go back 1 hour for good: 2:00 AM becomes 1:00 AM | UTC+10 |
Where Pacific/Guam is used
Pacific/Guam is used in Guam. These are the largest cities in our list that follow it.
Pacific/Guam compared with other time zones
Differences change during the year when one side moves to or from daylight saving time, so the table shows January and July separately.
| City | Time now | Difference now | In January | In July |
|---|---|---|---|---|
| New York (United States) | --:-- | 15 h behind | 15 h behind | 14 h behind |
| Los Angeles (United States) | --:-- | 18 h behind | 18 h behind | 17 h behind |
| London (United Kingdom) | --:-- | 10 h behind | 10 h behind | 9 h behind |
| Paris (France) | --:-- | 9 h behind | 9 h behind | 8 h behind |
| Dubai (United Arab Emirates) | --:-- | 6 h behind | 6 h behind | 6 h behind |
| Mumbai (India) | --:-- | 4 h 30 min behind | 4 h 30 min behind | 4 h 30 min behind |
| Singapore | --:-- | 2 h behind | 2 h behind | 2 h behind |
| Tokyo (Japan) | --:-- | 1 h behind | 1 h behind | 1 h behind |
| Sydney (Australia) | --:-- | 1 h ahead | 1 h ahead | Same time |
| UTC | --:-- | 10 h behind | 10 h behind | 10 h behind |
Other zones on UTC+10 right now
These IANA zones show the same time as Pacific/Guam today. Their clock-change rules may differ.
Using Pacific/Guam in software
Store and send the zone as its IANA name, Pacific/Guam, not as a fixed offset. A fixed offset such as UTC+10 gives the wrong result after the next clock change.
Show the current time in Pacific/Guam:
// JavaScript
new Intl.DateTimeFormat('en-GB', { timeZone: 'Pacific/Guam', timeStyle: 'long' }).format(new Date());
# Python
from datetime import datetime
from zoneinfo import ZoneInfo
datetime.now(ZoneInfo('Pacific/Guam'))
// PHP
(new DateTime('now', new DateTimeZone('Pacific/Guam')))->format('c');
# Shell
TZ=Pacific/Guam dateTools for time in Pacific/Guam
- Convert a time to or from Pacific/Guam: pick a date and time and see it in every city on your list.
- Add Dededo to your world clock to keep it next to your own time.
- Find a meeting time that falls inside office hours in Pacific/Guam and the other cities you work with.
- Open a full-screen clock for your own time zone.
Frequently asked questions
What is the UTC offset of Pacific/Guam?
UTC+10, all year.
What abbreviation does Pacific/Guam use?
ChST. Abbreviations are not unique, so use the zone name Pacific/Guam in software.
Time zone rules: IANA tz database, version 2026e. Place names and coordinates: GeoNames. Sunrise and sunset are calculated from the coordinates and can differ by a minute or two from local almanacs.