Time ZonesAbout this time zone
All of Guam keeps one time. Computers and phones know it by the zone name Pacific/Guam. Its time is UTC+10, which means it is 10 hours ahead of Coordinated Universal Time (UTC) all year round. The short name used for this time is ChST. Compared with India (IST), it is 4 hours 30 minutes ahead of India.
Clock changes in 2026 and 2027
Guam does not change its clocks in 2026 or 2027. The time stays at UTC+10 all year, so there is no daylight saving time to remember.
Time difference with major cities
| When it is 12:00 noon in Guam, it is | In January 2026 | In July 2026 |
|---|---|---|
| India | 7:30 am4 hours 30 minutes behind | 7:30 am4 hours 30 minutes behind |
| United Kingdom | 2:00 am10 hours behind | 3:00 am9 hours behind |
| France | 3:00 am9 hours behind | 4:00 am8 hours behind |
| New York, United States | 9:00 pm previous day15 hours behind | 10:00 pm previous day14 hours behind |
| Chicago, United States | 8:00 pm previous day16 hours behind | 9:00 pm previous day15 hours behind |
| Los Angeles, United States | 6:00 pm previous day18 hours behind | 7:00 pm previous day17 hours behind |
| United Arab Emirates | 6:00 am6 hours behind | 6:00 am6 hours behind |
| Singapore | 10:00 am2 hours behind | 10:00 am2 hours behind |
| Japan | 11:00 am1 hour behind | 11:00 am1 hour behind |
| Sydney, Australia | 1:00 pm1 hour ahead | 12:00 pmsame time |
The table uses the offsets in force in mid January and mid July 2026. Use the converter for any other date.
Clock time and sun time in Guam
A time zone is an agreement, and the sun does not follow it exactly. Dededo Village, the largest city in this zone, lies at about 144.8° east. Each degree of longitude is worth four minutes, so by the sun alone its time would be about 9 hours 39 minutes ahead of UTC. The clock is set to UTC+10. The sun is therefore highest in the sky at about 12:21 pm by the clock, not at 12:00. The clock runs ahead of the sun here, which means later sunrises and lighter evenings than the map alone would give. Other places in the zone, to the east or west of Dededo Village, see the sun peak a little earlier or later. Through the year the figure also drifts by up to a quarter of an hour either way.
How long the day is
Dededo Village is about 13.5° north of the equator. On the longest day of the year, around 21 June, the sun is up for about 12 hours 55 minutes. On the shortest, around 21 December, for about 11 hours 20 minutes. The difference between summer and winter is about 1 hour 36 minutes, and the clocks stay the same all year.
Office hours shared with other places
If both sides work from 9 am to 6 pm, these are the hours when a call falls inside the working day at both ends. Times are for Guam.
- With India, all year: 1:30 pm to 6:00 pm here, which is 9:00 am to 1:30 pm in India (4 hours 30 minutes shared).
- With London, in January: no shared office hour: 9:00 am here is 11:00 pm in London, and 6:00 pm here is 8:00 am there, so one side has to start early or stay late. In July: no shared office hour: 9:00 am here is 12:00 am in London, and 6:00 pm here is 9:00 am there, so one side has to start early or stay late.
- With New York, in January: no shared office hour: 9:00 am here is 6:00 pm in New York, and 6:00 pm here is 3:00 am there, so one side has to start early or stay late. In July: no shared office hour: 9:00 am here is 7:00 pm in New York, and 6:00 pm here is 4:00 am there, so one side has to start early or stay late.
How many people keep this time
The GeoNames list has 5 towns and cities of 15,000 people or more in this zone area, with about 101,000 people between them. People in villages and smaller towns are not in that count, so the true number on this clock is higher.
Cities that keep this time
The largest cities in this zone: Dededo Village, Yigo Village, Tamuning-Tumon-Harmon Village, Mangilao Village, Hagåtña.
Places with exactly the same time
These zones show the same time as Guam through the whole year: Vladivostok, Russia, Brisbane, Australia, Port Moresby, Papua New Guinea, Saipan, Northern Mariana Islands.
The clock above uses your device's clock and the time zone rules built into your browser. Rules on this page: IANA time zone database 2026f. See About and data sources.