ChST — Chamorro Standard Time
See where ChST (UTC+10) is used, check current local time, and compare it with other time zones worldwide.
Meaning and usage areas
ChST stands for Chamorro Standard Time and stays at UTC+10 year-round. It is used in Guam and the Northern Mariana Islands.
No daylight saving changes
ChST does not observe daylight saving time, so the offset remains UTC+10 throughout the year. Our data tracks this automatically using the IANA timezone database.
Convert ChST to others
Compare ChST with other time zones using the visual hour grid and time difference tables. Export meetings with ICS download or add them to Google Calendar and Gmail.
How to Convert ChST to Other Time Zones
Open the ChST converter page: Go to https://www.xconvert.com/time-converter/chst-time-zone to load a comparison grid with Chamorro Standard Time already in place. This is useful when you need to line up work hours in Guam or the Northern Mariana Islands with teams, clients, or travel contacts in other parts of the world.
Add comparison cities: Click + Add City and search for cities you want to compare against ChST. This is especially practical if you are coordinating calls involving Saipan, Tamuning, or Dededo Village and need to compare those schedules with offices, suppliers, or family in other regions.
Select a time range on the grid: Click Select, then drag across the colored hourly timeline on the ChST row to highlight a meeting window in purple. You can drag the center of the selection to move it, or use the left and right handles to resize it until you find a time that fits business hours, evening availability, or airport transfer timing for places using UTC+10.
Export and share the result: Once a range is selected, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This helps when you want everyone involved in a Guam or Northern Mariana Islands meeting to receive the same time block in their own local calendar without manual conversion mistakes.
About Chamorro Standard Time (ChST)
ChST stands for Chamorro Standard Time. It uses an exact offset of UTC+10, which means local time in this zone is ten hours ahead of Coordinated Universal Time.
Chamorro Standard Time is used in Guam and the Northern Mariana Islands. Principal cities and communities in this time zone include Dededo Village, Mangilao Village, Saipan, San Jose Village, Tamuning, Tamuning-Tumon-Harmon Village, and Yigo Village.
ChST does not observe daylight saving time and has no counterpart. That makes it a fixed year-round time standard, which is helpful for recurring scheduling because the offset remains UTC+10 throughout the year.
Other abbreviations that share the same UTC+10 offset include AEST, AET, CHUT, DDUT, K, PGT, VLAT, YAKST, and YAPT. Even when the offset matches, the abbreviation and region still matter for calendar labeling, travel itineraries, and international coordination.
ChST and Daylight Saving Time
Chamorro Standard Time does not switch for daylight saving time. It remains on UTC+10 all year and does not change to any summer or winter counterpart.
Because ChST has no DST observance and no counterpart, there are no transition dates during the current year. This consistency is useful for long-term planning in Guam and the Northern Mariana Islands, especially for recurring calls, school schedules, transport planning, and administrative coordination.
A fixed time zone also reduces confusion when comparing schedules across multiple regions. If you are arranging meetings involving Saipan or Tamuning, the ChST side of the schedule stays stable even when other countries shift their clocks seasonally.
Frequently Asked Questions
What does ChST stand for?
ChST stands for Chamorro Standard Time. It is the standard time used in Guam and the Northern Mariana Islands, and it stays at UTC+10 throughout the year.
The abbreviation is important in calendars, airline schedules, and meeting planning because it identifies the local time standard used in these Pacific locations. Using the full name can also help avoid confusion with other time zones that share the same UTC offset.
Is ChST the same as GMT?
No. ChST is UTC+10, while GMT is not the same offset as ChST. That means Chamorro Standard Time is ten hours ahead of UTC and should not be treated as equivalent to GMT in scheduling.
This distinction matters when booking calls, flights, or deadlines involving Guam or the Northern Mariana Islands. Using the wrong reference can shift an appointment by many hours, which is a common issue in international coordination.
Which cities use ChST?
Cities and communities using ChST include Dededo Village, Mangilao Village, Saipan, San Jose Village, Tamuning, Tamuning-Tumon-Harmon Village, and Yigo Village. These places are located in Guam and the Northern Mariana Islands.
If you are planning business communication, travel timing, or family calls with people in these locations, ChST is the time zone to use. Listing the city correctly in a world clock or calendar invite helps ensure the right local time is applied.
What is the UTC offset for ChST?
The UTC offset for ChST is UTC+10. This means local time in Chamorro Standard Time is ten hours ahead of Coordinated Universal Time.
A fixed offset is especially useful for recurring schedules because it does not change during the year. For teams working with Guam or Saipan, that consistency makes planning easier on the ChST side even if other regions move in and out of daylight saving time.
When does ChST change?
ChST does not change during the year. It does not observe daylight saving time, and it has no counterpart that it switches to seasonally.
As a result, there are no spring or autumn clock changes to track in Guam or the Northern Mariana Islands. This makes ChST straightforward for annual planning, standing meetings, and travel coordination.
Does Chamorro Standard Time observe daylight saving time?
No, Chamorro Standard Time does not observe daylight saving time. It stays on UTC+10 for the entire year.
That means there is no separate daylight abbreviation and no annual clock adjustment to account for. For users scheduling across multiple countries, this reduces one source of confusion because ChST remains constant while other regions may shift.
Are there other time zone abbreviations with the same offset as ChST?
Yes. Other abbreviations with the same UTC+10 offset are AEST, AET, CHUT, DDUT, K, PGT, VLAT, YAKST, and YAPT. These share the same numerical offset from UTC as ChST.
Even so, they are not interchangeable in every context because the abbreviation often signals a specific region. For calendar invites, logistics planning, and official documents, using ChST is the clearest choice when referring to Guam or the Northern Mariana Islands.