Time zone for Guam and Northern Mariana Islands
The
Chamorro Time Zone
,
[1]
formerly the
Guam Time Zone
, is a
United States time zone
which observes
standard time
ten hours ahead of
Coordinated Universal Time
(
UTC+10:00
). The clock time in this zone is based on the
mean solar time
of the
150th meridian east
of the
Greenwich Observatory
.
The zone includes the
U.S. territories
of
Guam
and the
Northern Mariana Islands
, where the
Chamorro people
are the original inhabitants. Since
Daylight Saving Time
(DST) is not observed anywhere in this zone, the time is always known as
Chamorro Standard Time
(ChST).
The zone is two hours behind
Wake Island Time Zone
and 15 hours ahead of North American
Eastern Time Zone
. As of March 19, 2024 it is the easternmost (farthest ahead) time zone shown on the U.S. government's time.gov webpage. Although
Wake
,
Howland
and
Baker Islands
are U.S. territories in more easterly time zones (that are not shown), they are uninhabited.
Chamorro Standard Time shares the same time as
Australian Eastern Standard Time
. The State of
Queensland
also does not observe DST, so the Commonwealth of the Northern Mariana Islands (CNMI), Guam and Queensland are on the same time year round.
Populated areas and major cities
[
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]
History
[
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]
Until Monday, December 30, 1844,
Guam
and
Mariana Islands
belonged to
Captaincy General of the Philippines
, which had the date of the western hemisphere on their island, placing them on the eastern side of the
International Date Line
(IDL). On Wednesday, January 1, 1845, they switched to the date of the eastern hemisphere on the western side of the IDL, skipping the entire calendar day of Tuesday, December 31, 1844.
[
citation needed
]
Before time zones were introduced, every place used local observation of the sun to set its clocks, which meant that every location used a different local mean time based on its longitude. For example, Hagatna, the capital of Guam at the time, at longitude 144°45′E, had a local time equivalent to GMT-14:21 under the date of the western hemisphere and GMT+09:39 under the eastern hemisphere.
[
citation needed
]
In 1901, "Guam Standard Time" was established within the United States as GMT+10:00.
[
citation needed
]
The U.S. Congress formally created Chamorro Standard Time by federal Public Law 106-564 on December 23, 2000. Previously,
Guam
Standard Time existed per territorial Public Law 5-25 (1959).
[2]
This statute is still on the territorial law books, although it is preempted by the federal law.
[
citation needed
]
The Northern Mariana Islands, as part of the
Trust Territory of the Pacific Islands
, were not part of any American time zone prior to becoming a U.S. Commonwealth on January 1, 1978. Being directly north of Guam, however, they observed the same time.
[
citation needed
]
See also
[
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]
References
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]
Sources
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]