ChST to GMT Converter
The United Kingdom is on summer time: BST (UTC+1) until Sun, Oct 25.
Iceland and Ghana stay on GMT (UTC+0).
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Add one or more places to compare local times, adjust the date, and share the result.
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Selected conversion
10:00 pm22:00 ChST (UTC+10), Oct 13, 2026 = 12:00 pm12:00 GMT (UTC+0), Oct 13, 2026
ChST is 10 hours ahead of GMT.
ChST and GMT examples
These examples always use ChST (UTC+10) and GMT (UTC+0). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
ChST is 10 hours ahead of GMT.
How the time difference changes
ChST is 10 hours ahead of GMT year-round.
Working hours of 9:00 am to 5:00 pm in ChST correspond to 11:00 pm (previous day) to 7:00 am in GMT.Working hours of 09:00 to 17:00 in ChST correspond to 23:00 (previous day) to 07:00 in GMT.
Compare ChST time with GMT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Chamorro Standard Time is 10 hours ahead of Greenwich Mean Time.
10:00 pm22:00 in ChST is 12:00 pm12:00 in GMT
ChST to GMT call time
Best time for a conference call or a meeting is between 5:30pm-6:30pm17:30-18:30 in ChST which corresponds to 7:30am-8:30am07:30-08:30 in GMT. Their 9am–5pm09:00–17:00 working hours do not overlap; this is a suggested compromise.
10:00 pm22:00 Chamorro Standard Time (ChST). Offset UTC +10:00 hours
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
10:00 pm22:00 ChST / 12:00 pm12:00 GMT
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
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Chamorro Standard Time
Offset: ChST is 10 hours ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Guam, Northern Mariana Islands
Principal Cities: The largest city in the ChST time zone is Saipan in the Northern Mariana Islands, with about 48,220 people. Other major cities in this time zone include Dededo Village, Yigo Village, Tamuning-Tumon-Harmon Village, Mangilao Village.
Daylight Saving: Clocks in Chamorro Standard Time (ChST) do not change for daylight saving time, so ChST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.
ChST representations, usage and related time zones
- +10 - basic short
- +1000 - basic
- +10:00 - extended
- +1000 - sign character (+) followed by a four digit time providing hours (10) and minutes (00) of the offset. Indicates an offset of ten hours to the east of the zero meridian.
- Kilo - Military abbreviation for ChST
- K - short form of 'Kilo'
- Pacific/Guam
- Pacific/Saipan
- AEST - Australian Eastern Standard Time
- CHUT - Chuuk Time
- ChST - Chamorro Standard Time
- K - Kilo Time Zone
- KDT - Korea Daylight Time
- PGT - Papua New Guinea Time
- VLAT - Vladivostok Time
- YAKST - Yakutsk Summer Time
- YAPT - Yap Time
Greenwich Mean Time
Offset: GMT is the same as Greenwich Mean Time (GMT).
Countries using this time zone: Burkina Faso, Côte d'Ivoire, Britain (UK), Guernsey, Ghana, Greenland, Gambia, Guinea, Guinea-Bissau, Ireland, Isle of Man, Iceland, Jersey, Liberia, Mali, Mauritania, St Helena, Sierra Leone, Senegal, Sao Tome & Principe, Togo
Principal Cities: The largest city in the GMT time zone is London in the United Kingdom, with about 8.962 million people. Other major cities in this time zone include Abidjan, Bamako, Dakar, Kumasi.
Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use the two are the same. In the military, GMT is known as Zulu time. Greenwich Mean Time was the same as Universal Time (UT), a standard astronomical concept used in many technical fields, until the introduction of UTC in 1972.
GMT representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for GMT
- Z - short form of 'Zulu'
- Africa/Abidjan
- Africa/Accra
- Africa/Bamako
- Africa/Banjul
- Africa/Bissau
- Africa/Conakry
- Africa/Dakar
- Africa/Freetown
- Africa/Lome
- Africa/Monrovia
- Africa/Nouakchott
- Africa/Ouagadougou
- Africa/Sao_Tome
- Africa/Timbuktu
- America/Danmarkshavn
- Atlantic/Reykjavik
- Atlantic/St_Helena
- Eire
- Etc/GMT
- Etc/GMT+0
- Etc/GMT-0
- Etc/GMT0
- Etc/Greenwich
- Europe/Belfast
- Europe/Dublin
- Europe/Guernsey
- Europe/Isle_of_Man
- Europe/Jersey
- Europe/London
- GB
- GB-Eire
- GMT
- GMT+0
- GMT-0
- GMT0
- Greenwich
- Iceland
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Coordinated Universal Time
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone
