Reunified

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

follows

Indochina Time UTC+07:00 is an identifier for a time offset from UTC of +07:00. In ISO 8601 the associated time would be written as . It is 7 hours ahead of UTC, meaning that when the time in UTC areas is midnight (00:00), the time in UTC+07:00 areas would ...

(ICT), which is seven hours ahead of UTC, ICT is used all year round as Vietnam does not observe

daylight saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...

. Vietnam shares the same time zone with

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

Cambodia Cambodia, officially the Kingdom of Cambodia, is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. It is bordered by Thailand to the northwest, Laos to the north, and Vietnam to the east, and has a coastline ...

Christmas Island Christmas Island, officially the Territory of Christmas Island, is an States and territories of Australia#External territories, Australian external territory in the Indian Ocean comprising the island of the same name. It is about south o ...

Laos Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and ...

, and Western

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

. Vietnam referenced

ISO 8601 ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It is maintained by the International Organization for Standardization (ISO) and was first published in 1988, with updates in ...

under in 1998 and then created its own standard TCVN 6398-1:1998.

History

* After Phủ Liễn Observatory was built, French Indochina announced all states (consisting of north-Vietnamese Tonkin, central-Vietnamese Annam, south-Vietnamese

Cochinchina Cochinchina or Cochin-China (, ; ; ; ; ) is a historical exonym and endonym, exonym for part of Vietnam, depending on the contexts, usually for Southern Vietnam. Sometimes it referred to the whole of Vietnam, but it was commonly used to refer t ...

, as well as

and Chinese

Guangzhouwan The Leased Territory of Guangzhouwan, officially the and historically known in English as Kwangchowan or Kwangchow Wan, was a coastal territory of Zhanjiang, China leased to France and administered by French Indochina. The capital of the t ...

) were part of 104°17′17″E longitude east of Paris meridian 2°20′14″E, or 106°37′30″E from

Greenwich Mean Time Greenwich Mean Time (GMT) is the local mean time at the Royal Observatory, Greenwich, Royal Observatory in Greenwich, London, counted from midnight. At different times in the past, it has been calculated in different ways, including being ...

from 00:00, 1 July 1906 onward. * In 1911,

Metropolitan France Metropolitan France ( or ), also known as European France (), is the area of France which is geographically in Europe and chiefly comprises #Hexagon, the mainland, popularly known as "the Hexagon" ( or ), and Corsica. This collective name for the ...

adopted UTC+00:00 (the

solar time Solar time is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the day, based on the synodic rotation period. Traditionally, there are three types of time reckoning based ...

Greenwich Greenwich ( , , ) is an List of areas of London, area in south-east London, England, within the Ceremonial counties of England, ceremonial county of Greater London, east-south-east of Charing Cross. Greenwich is notable for its maritime hi ...

) as its official time, and used it until 1940 (with UTC+01:00 used during the summers from 1916 to 1940), forcing French Indochina observed UTC+07:00 from 00:00, 1 May 1911. * Following change in time zone of Vichy authorities, French Indochina was integrated to UTC+08:00 skipping 60 minutes at 23:00, 31 December 1942. * The

Empire of Japan The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the Japanese nation state that existed from the Meiji Restoration on January 3, 1868, until the Constitution of Japan took effect on May 3, 1947. From Japan–Kor ...

occupied Vichy French Indochina fully. Indochinese regions thereafter followed Tokyo time zone (UTC+09:00), skipping 60 minutes at 23:00, 14 March 1945. * By August General Uprising, the Fall of

Empire of Vietnam The Empire of Vietnam (; Literary Chinese and Japanese language, Contemporary Japanese: ; Japanese language, Modern Japanese: ) was a short-lived Japanese puppet state, puppet state of Empire of Japan, Imperial Japan between March 11 and Abdicat ...

and the Proclamation of Independence of the Democratic Republic of Vietnam, Provisional Uniform Government of the

Democratic Republic of Vietnam North Vietnam, officially the Democratic Republic of Vietnam (DRV; ; VNDCCH), was a country in Southeast Asia from 1945 to 1976, with sovereignty fully recognized in 1954. A member of the communist Eastern Bloc, it opposed the French-suppor ...

took control, announcing UTC+07:00 as official time zone on 2 September 1945. Whilst, the then under-attack regions of Vietnam, Laos and Cambodia adopted UTC+08:00 and non-attacked regions (at the time and even after the 1954 Geneva Conference) adopted UTC+07:00 from

April 1 Events Pre-1600 * 527 – Byzantine Emperor Justin I names his nephew Justinian I as co-ruler and successor to the throne. * 1081 – Alexios I Komnenos overthrows the Byzantine emperor Nikephoros III Botaneiates, and, after his tro ...

, 1947: Laos (part of Indochina) from 15 April 1954, Hanoi from October 1954, Haiphong from May 1955. * Under control of State of Vietnam, South Vietnam adopted UTC+07:00 from 00:00, 1 July 1955. *South Vietnam time zone was changed to UTC+08:00 from 23:00, 31 December 1959, passing 60 minutes. *North Vietnam confirmed official UTC+07:00 from 1 January 1968. *Following the

Fall of Saigon The fall of Saigon, known in Vietnam as Reunification Day (), was the capture of Saigon, the capital of South Vietnam, by North Vietnam on 30 April 1975. As part of the 1975 spring offensive, this decisive event led to the collapse of the So ...

in April–May 1975, reunified Vietnam then observes UTC+07:00 with

Saigon Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025. The city's geography is defined by rivers and canals, of which the largest is Saigo ...

(and other southern parts) delaying 60 minutes on 13 June 1975.

Time in
French Indochina French Indochina (previously spelled as French Indo-China), officially known as the Indochinese Union and after 1941 as the Indochinese Federation, was a group of French dependent territories in Southeast Asia from 1887 to 1954. It was initial ...

Time in
North Vietnam North Vietnam, officially the Democratic Republic of Vietnam (DRV; ; VNDCCH), was a country in Southeast Asia from 1945 to 1976, with sovereignty fully recognized in 1954 Geneva Conference, 1954. A member of the communist Eastern Bloc, it o ...

Time in
South Vietnam South Vietnam, officially the Republic of Vietnam (RVN; , VNCH), was a country in Southeast Asia that existed from 1955 to 1975. It first garnered Diplomatic recognition, international recognition in 1949 as the State of Vietnam within the ...

Time in Reunified Vietnam

References

Bibliography

* Trần Tiến Bình (2005), ''Lịch Việt Nam thế kỷ XX-XXI (1901–2100)'', Nhà xuất bản Văn hoá Thông tin, Hanoi. Geography of Vietnam

{{standard-stub

History

Time in French Indochina French Indochina (previously spelled as French Indo-China), officially known as the Indochinese Union and after 1941 as the Indochinese Federation, was a group of French dependent territories in Southeast Asia from 1887 to 1954. It was initial ...

Time in North Vietnam North Vietnam, officially the Democratic Republic of Vietnam (DRV; ; VNDCCH), was a country in Southeast Asia from 1945 to 1976, with sovereignty fully recognized in 1954 Geneva Conference, 1954. A member of the communist Eastern Bloc, it o ...