ChST — Chamorro Standard Time
See what ChST means, where it is used, and convert Chamorro Standard Time to other time zones with live comparison tools.
Meaning and Regions Used
ChST stands for Chamorro Standard Time and uses a fixed UTC+10 offset. It is observed in Guam and the Northern Mariana Islands year-round.
No DST Time Changes
Chamorro Standard Time does not observe daylight saving time, so the offset stays at UTC+10 all year. This page tracks rule stability and historical timezone updates.
Convert ChST Across Zones
Compare ChST with other time zones using the visual hour-by-hour grid and scheduling table. Export meetings with ICS download or send 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 open the visual comparison grid with Chamorro Standard Time pre-loaded. This is useful when you need to line up working hours in Guam or the Northern Mariana Islands with teams, customers, or travel schedules in other parts of the world.
Add comparison cities: Click + Add City and search for cities you want to compare against ChST. Good choices depend on your use case: add major business hubs for remote team coordination, airline planning, or customer support coverage, then compare them against ChST locations such as Dededo Village, Yigo Village, Tamuning, Tamuning-Tumon-Harmon Village, Mangilao Village, Saipan, and San Jose Village.
Select a time range on the grid: Use the Select button if needed, then drag across the 24-hour timeline in the ChST row to highlight a meeting window in purple. You can resize the range with the left and right handles or drag the center to test different options, which is especially helpful when trying to find overlap between daytime hours in Guam or Saipan and business hours in another region.
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. That makes it easy to send a confirmed meeting window to a distributed team, attach it to travel planning, or share a time-specific handoff schedule so everyone sees the event in their own local time.
About Chamorro Standard Time (ChST)
ChST stands for Chamorro Standard Time. It is set at UTC+10, meaning 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. Important population centers and commonly referenced places in this time zone include Dededo Village, Yigo Village, Tamuning, Tamuning-Tumon-Harmon Village, Mangilao Village, Saipan, and San Jose Village.
ChST is a fixed standard time with no daylight saving counterpart. That makes it simpler for scheduling because the abbreviation stays the same year-round and does not switch to a summer or winter variant.
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 local region and naming convention differ, so it is still important to confirm the exact city or time zone label when booking meetings or travel.
ChST and Daylight Saving Time
Chamorro Standard Time does not observe DST. It remains on UTC+10 throughout the entire year.
There is no seasonal switch, no summer-time version, and no counterpart abbreviation that replaces ChST during part of the year. For practical scheduling, that means a meeting planned in ChST for Guam or the Northern Mariana Islands keeps the same time-zone label and UTC offset in every month.
This consistency is useful for recurring coordination with contacts in Saipan, Dededo Village, or Tamuning, because the ChST side of the schedule does not move. If a meeting time changes during the year, the change comes from the other location’s daylight saving rules rather than from Chamorro Standard Time itself.
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 on the same offset all year.
Because the abbreviation does not change seasonally, ChST is straightforward to use for recurring schedules. If you work with people in Saipan or Tamuning, you can keep using the same abbreviation in calendar invites year-round.
Is ChST the same as GMT?
No. ChST is UTC+10, so it is ten hours ahead of GMT/UTC rather than the same as it.
That difference matters when scheduling calls, flights, or deadlines across regions. If a document or meeting is marked in ChST, it should not be treated as Greenwich-based time because the local clock in Guam or the Northern Mariana Islands is significantly ahead.
Which cities use ChST?
ChST is used in places across Guam and the Northern Mariana Islands. Principal cities and communities associated with this time zone include Dededo Village, Yigo Village, Tamuning, Tamuning-Tumon-Harmon Village, Mangilao Village, Saipan, and San Jose Village.
These are the kinds of locations you may see in scheduling tools, travel itineraries, or regional operations planning. If your meeting involves Guam or the Northern Mariana Islands, ChST is the time standard you should expect to see.
What is the UTC offset for ChST?
The UTC offset for Chamorro Standard Time is UTC+10. This means local time is ten hours ahead of Coordinated Universal Time.
That fixed offset is useful for international coordination because it does not shift during the year. When you compare ChST with another region, the ChST side remains stable while other time zones may change if they observe daylight saving time.
When does ChST change?
ChST does not change during the year. It does not observe daylight saving time and has no counterpart that replaces it seasonally.
There are no DST start dates, end dates, or clock-change weekends to track for ChST. For recurring meetings with contacts in Guam or Saipan, this removes one common source of scheduling errors.
Does ChST have a daylight saving version?
No, ChST has no daylight saving version. The abbreviation remains ChST all year, and the offset remains UTC+10.
This makes ChST easier to manage than time zones that alternate between standard and daylight names. If you are creating long-term schedules for operations in the Northern Mariana Islands or Guam, you do not need to update the time-zone label seasonally.
Are there other time zones with the same UTC+10 offset as ChST?
Yes. Other abbreviations that share the same UTC+10 offset include AEST, AET, CHUT, DDUT, K, PGT, VLAT, YAKST, and YAPT.
Even so, matching offsets do not always mean the same region or the same naming convention. For calendars, travel bookings, and operational planning, it is best to use the exact local zone name—such as Chamorro Standard Time—when your event is tied to Guam or the Northern Mariana Islands.