Japan Standard Time

Last updated
Japan Standard Time
Standard World Time Zones.png
UTC offset
JST UTC+09:00
Current time
09:29, 15 July 2019 JST [refresh]
Observance of DST
DST is not observed in this time zone.
Imperial Ordinance 167 issued on December 27, Meiji 28 (1895). Imperial Ordinance 167 issued on December 27, Meiji 28 (1895).png
Imperial Ordinance 167 issued on December 27, Meiji 28 (1895).

{{Nihongo|Japan Standard Time|日本標準時|Nihon Hyōjunji|extra={{IPA-ja|nihon hyougungi} or {{Nihongo||中央標準時|Chūō Hyōjunji|extra={{IPA-japan hyougungi }, JST}} is the standard timezone in Japan, 9 hours ahead of UTC (i.e. it is UTC+09:00). [1] There is no daylight saving time, though its introduction has been debated several times. During World War II, it was often called Tokyo Standard Time.

Japan Country in East Asia

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south.

Coordinated Universal Time Primary time standard by which the world regulates clocks and time

Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude, and is not adjusted for daylight saving time. In some countries where English is spoken, the term Greenwich Mean Time (GMT) is often used as a synonym for UTC and predates UTC by nearly 300 years.

UTC+09:00 identifier for a time offset from UTC of +9

UTC+09:00 is an identifier for a time offset from UTC of +09:00.


Japan Standard Time is the same as Korean Standard Time, Indonesian Eastern Standard Time, East-Timorese Standard Time and Yakutsk Time (Russia).

Time in South Korea Timezone of South Korea

South Korea has one time zone, Korea Standard Time (UTC+09:00), which is abbreviated KST. South Korea does not currently observe daylight saving time, but experimented with it during the 1988 Summer Olympics in Seoul.

Time in Indonesia

The Indonesian archipelago geographically stretches across four time zones from UTC+06:00 in Aceh to UTC+09:00 in Western New Guinea. However, the Indonesian government only recognizes three time zones in its territory:

East Timor uses UTC+09:00. In the west the country borders the UTC+08:00 zone of Indonesia and in the east the UTC+09:00 zone of that country. Daylight saving time is never observed in East Timor, due to its proximity to the equator, there is only a small variation between the length of day and night throughout the year.


Before the Meiji era (1868–1912), each local region had its own timezone in which noon was when the sun was exactly at its zenith. As modern transportation methods, such as trains, were adopted, this practice became a source of confusion. For example, there is a difference of about 5 degrees longitude between Tokyo and Osaka and because of this, a train that departed from Tokyo would arrive at Osaka 20 minutes behind the time in Tokyo. In 1886, Ordinance 51 was issued in response to this problem, which stated:

Meiji (era) Japanese era 1868–1912

The Meiji era is an era of Japanese history which extended from October 23, 1868 to July 30, 1912. This era represents the first half of the Empire of Japan, during which period the Japanese people moved from being an isolated feudal society at risk of colonisation by European powers to the new paradigm of a modern, industrialised nationstate and emergent great power, influenced by Western scientific, technological, philosophical, political, legal, and aesthetic ideas. As a result of such wholesale adoption of radically-different ideas, the changes to Japan were profound, and affected its social structure, internal politics, economy, military, and foreign relations. The period corresponded to the reign of Emperor Meiji and was succeeded upon the accession of Emperor Taishō by the Taishō era.


The zenith is an imaginary point directly "above" a particular location, on the imaginary celestial sphere. "Above" means in the vertical direction opposite to the apparent gravitational force at that location. The opposite direction, i.e. the direction in which gravity pulls, is toward the nadir. The zenith is the "highest" point on the celestial sphere.

Tokyo Capital of Japan

Tokyo, officially Tokyo Metropolis, one of the 47 prefectures of Japan, has served as the Japanese capital since 1869. As of 2018, the Greater Tokyo Area ranked as the most populous metropolitan area in the world. The urban area houses the seat of the Emperor of Japan, of the Japanese government and of the National Diet. Tokyo forms part of the Kantō region on the southeastern side of Japan's main island, Honshu, and includes the Izu Islands and Ogasawara Islands. Tokyo was formerly named Edo when Shōgun Tokugawa Ieyasu made the city his headquarters in 1603. It became the capital after Emperor Meiji moved his seat to the city from Kyoto in 1868; at that time Edo was renamed Tokyo. Tokyo Metropolis formed in 1943 from the merger of the former Tokyo Prefecture and the city of Tokyo. Tokyo is often referred to as a city but is officially known and governed as a "metropolitan prefecture", which differs from and combines elements of a city and a prefecture, a characteristic unique to Tokyo.

Ordinance 51 (on the precise calculation of time using the Prime Meridian) – July 13, 1886

Prime meridian A line of longitude, at which longitude is defined to be 0°

A prime meridian is a meridian in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its anti-meridian form a great circle. This great circle divides a spheroid, e.g., Earth, into two hemispheres. If one uses directions of East and West from a defined prime meridian, then they can be called the Eastern Hemisphere and the Western Hemisphere.

Royal Observatory, Greenwich observatory in Greenwich, London, UK

The Royal Observatory, Greenwich is an observatory situated on a hill in Greenwich Park, overlooking the River Thames. It played a major role in the history of astronomy and navigation, and is best known for the fact that the prime meridian passes through it, and thereby gave its name to Greenwich Mean Time. The ROG has the IAU observatory code of 000, the first in the list. ROG, the National Maritime Museum, the Queen's House and Cutty Sark are collectively designated Royal Museums Greenwich.

Akashi Municipal Planetarium, located exactly on 135degE longitude, and known as a symbol of Japan Standard Time. Akashi Minicipal Planetarium.JPG
Akashi Municipal Planetarium, located exactly on 135°E longitude, and known as a symbol of Japan Standard Time.

According to this, the standard time(標準時,Hyōjunji) was set 9 hours ahead of GMT (UTC had not been established yet). In the ordinance, the first clause mentions GMT, the second defines east longitude and west longitude and the third says the standard timezone would be in effect from 1888. The city of Akashi in Hyōgo Prefecture is located exactly on 135 degrees east longitude and subsequently became known as Toki no machi (Town of Time).

Greenwich Mean Time time zone

Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, reckoned from midnight. At different times in the past, it has been calculated in different ways, including being calculated from noon; as a consequence, it cannot be used to specify a precise time unless a context is given.

Akashi, Hyōgo Core city in Kansai, Japan

Akashi is a city located in southern Hyōgo Prefecture, Japan, on the Seto Inland Sea west of Kobe.

Hyōgo Prefecture Prefecture of Japan

Hyōgo Prefecture is a prefecture of Japan located in the Kansai region on Honshu island. The capital of Hyogo is Kobe.

With the annexation of Taiwan in 1895, Ordinance 167 (pictured on the right) was issued to rename the previous Standard Time to Central Standard Time(中央標準時,Chūō Hyōjunji) and establish a new Western Standard Time(西部標準時,Seibu Hyōjunji) at 120° longitude as the time zone for the Japanese Miyako and Yaeyama Islands, as well as Taiwan and its Penghu Islands. [3] While Korea came under Japanese rule in 1910, Korea Standard Time of UTC+08:30 continued to be used until 1912, when it was changed to Central Standard Time.

Taiwan under Japanese rule Period of Taiwanese history

Japanese Taiwan was the period of Taiwan and the Penghu Islands under Japanese rule between 1895 and 1945.

Miyako Islands group of islands in Okinawa Prefecture, Japan

The Miyako Islands are a group of islands in Okinawa Prefecture, Japan, east of the Yaeyama Islands. They are situated between the Ryukyu Islands and Taiwan.

Yaeyama Islands island group

The Yaeyama Islands are an archipelago in the southwest of Okinawa Prefecture, Japan, and cover 591.46 square kilometres (228.36 sq mi). The islands are located southwest of the Miyako Islands, part of the Ryukyu Islands archipelago. The Yaeyama Islands are the remotest part of Japan from the main islands and contain Japan's most southern (Hateruma) and most western (Yonaguni) inhabited islands. The city of Ishigaki serves as the political, cultural, and economic center of the Yaeyama Islands.

Western Standard Time, which was used in Taiwan and some parts of Okinawa, was abolished by Ordinance 529 in 1937 and replaced by Central Standard Time in those areas. [4] Territories occupied by Japan during World War II, including Singapore and Malaya, adopted Japan Standard Time for the duration of their occupation, but reverted after Japan's surrender.

In 1948–1951 occupied Japan observed daylight saving time (DST) from the first Sunday in May at 02:00 to the second Saturday in September at 02:00, except that the 1949 spring-forward transition was the first Sunday in April. [5] More recently there have been efforts to bring back DST in Japan, but so far this has not happened. [6] [7]

Time zones of the Japanese Empire

The two-time-zone system was implemented in Japan between January 1896 and September 1937:

Time offsetNameJapaneseRomanizationRegion
UTC+08:00 Western Standard Time西部標準時Seibu HyōjunjiWestern Okinawa and Taiwan (see also Time in Taiwan)
UTC+09:00 Central Standard Time中央標準時Chūō HyōjunjiJapan mainland and Korea (see also Korea Standard Time)

From October 1937, Central Standard Time was also used in western Okinawa and Taiwan.

IANA time zone database

The IANA time zone database contains one zone for Japan in the file zone.tab, named Asia/Tokyo.

Daylight saving time in Japan

From 194852, Japan observed DST between May and September every year. The US imposed this policy as part of the Allied occupation of Japan. In 1952, three weeks before the occupation ended, the Japanese government, which had been granted increased powers, abolished daylight savings time, and the Allied occupation authorities did not interfere. [8] Since then, DST has never been officially implemented nationwide in Japan. [9]

Starting in the late 1990s, a movement to reinstate DST in Japan gained some popularity, aiming at saving energy and increasing recreational time. The Hokkaido region is particularly in favor of this movement because daylight starts as early as 03:30 (in standard time) there in summer due to its high latitude and its location near the eastern edge of the time zone, with much of the region's solar time actually closer to UTC+10:00. Because of this, the sun sets barely after 19:00 in much of the eastern part of the country (in Tokyo, the latest sunset of the entire year is 19:01, from June 26 to July 1, despite being at 35°41'N latitude). After 2000, a few local governments and commerce departments promoted unmandated hour-earlier work schedule experiments during the summer without officially resetting clocks. [10]

In May 2013, former Tokyo governor Naoki Inose proposed permanently moving the country’s time zone ahead by 2 hours to UTC+11:00 to better align global markets and make Japan’s stock market to be the first to open in the world at any given time.

In 2018 Japan considered introducing daylight saving time for the 2020 Tokyo Olympic Games to make the 2020 Tokyo Olympic Games stage events during cooler hours.

This idea would move the clocks forward by 1 hour to UTC+10:00 or 2 hours to UTC+11:00 during the 2020 Tokyo Olympic Games.

On 27, September 2018 the organizers of the 2020 Tokyo Olympic Games announced that Japan will not introduce daylight saving time for the 2020 Tokyo Olympic Games due to a lack of support from businesses and the public.

[11] However, it is not clear that DST would conserve energy in Japan. A 2007 simulation estimated that introducing DST to Japan would increase energy use in Osaka residences by 0.13%, with a 0.02% saving due to lighting more than outweighed by a 0.15% increase due to cooling costs; the simulation did not examine non-residential buildings. [12]

See also

Related Research Articles

A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. Time zones tend to follow the boundaries of countries and their subdivisions because it is convenient for areas in close commercial or other communication to keep the same time.

Indian Standard Time time zone, observed in India and Sri Lanka; UTC+05:30

Indian Standard Time (IST) is the time observed throughout India, with a time offset of UTC+05:30. India does not observe daylight saving time (DST) or other seasonal adjustments. In military and aviation time IST is designated E* ("Echo-Star").

Hawaii–Aleutian Time Zone UTC−10:00 during standard time; UTC−09:00 during daylight saving

The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST), by subtracting ten hours from Coordinated Universal Time (UTC−10:00). The clock time in this zone is based on the mean solar time of the 150th meridian west of the Greenwich Observatory.

Time in the United States Timekeeping in the USA

Time in the United States, by law, is divided into nine standard time zones covering the states and its possessions, with most of the United States observing daylight saving time (DST) for approximately the spring, summer, and fall months. The time zone boundaries and DST observance are regulated by the Department of Transportation. Official and highly precise timekeeping services (clocks) are provided by two federal agencies: the National Institute of Standards and Technology (NIST) ; and its military counterpart, the United States Naval Observatory (USNO). The clocks run by these services are kept synchronized with each other as well as with those of other international timekeeping organizations.

The Atlantic Time Zone is a geographical region that keeps standard time—called Atlantic Standard Time (AST)—by subtracting four hours from Coordinated Universal Time (UTC), resulting in UTC−04:00. During part of the year, some portions of the zone observe daylight saving time, referred to as Atlantic Daylight Time (ADT), by moving their clocks forward one hour to result in UTC−03:00. The clock time in this zone is based on the mean solar time of the 60th meridian west of the Greenwich Observatory.

UTC+03:00 Identifier for a time offset from UTC of +03:00

UTC+03:00 is an identifier for a time offset from UTC of +03:00. In areas using this time offset, the time is three hours later than the Coordinated Universal Time (UTC). Following the ISO 8601 standard, a time with this offset would be written as, for example, 2019-02-08T23:36:06+03:00.

Time in Australia country with three main time zones

Australia uses three main time zones: Australian Western Standard Time, Australian Central Standard Time, and Australian Eastern Standard Time. Time is regulated by the individual state governments, some of which observe daylight saving time (DST). Australia's external territories observe different time zones.

The time in China follows a single standard time offset of UTC+08:00, despite China spanning five geographical time zones. The official national standard time is called Beijing Time domestically and China Standard Time (CST) internationally. Daylight saving time has not been observed since 1991.

Time in Canada

Canada is divided into six time zones, based on proposals by Scottish Canadian railway engineer Sir Sandford Fleming, who pioneered the use of the 24-hour clock, the world's time zone system, and a standard prime meridian. Most of Canada operates on standard time from the first Sunday in November to the second Sunday in March and daylight saving time the rest of the year.

Time in Chile is divided into three time zones. Most of Continental Chile uses the time offset UTC−04:00 in winter time and UTC−03:00 in summer time, while the Magallanes and Chilean Antarctica region uses the time offset UTC-03:00 the whole year. Additionally, Easter Island uses the time offset UTC−06:00 in winter time and UTC−05:00 in summer time

Malaysian Standard Time or Malaysian Time (MYT) is a standard time used in Malaysia. It is 8 hours ahead of Greenwich Mean Time and Coordinated Universal Time. The local mean time in Kuala Lumpur was originally UTC+06:46:46. Peninsular Malaysia used this local mean time until 1 January 1901, when they changed to Singapore mean time UTC+06:55:25. Between the end of the Second World War and the formation of Malaysia on 16 September 1963, it was known as British Malayan Standard Time, which was UTC+07:30 hours ahead of Greenwich Mean Time. At 2330 hrs local time of 31 December 1981, people in Peninsular Malaysia adjusted their clocks and watches ahead by 30 minutes to become 00:00 hours local time of 1 January 1982, to match the time in use in East Malaysia, which is UTC+08:00. SGT (Singapore) as follow on the same until now.

The UTC offset is the difference in hours and minutes from Coordinated Universal Time (UTC) for a particular place and date. It is generally shown in the format ±[hh]:[mm], ±[hh][mm], or ±[hh]. So if the time being described is one hour ahead of UTC, the UTC offset would be "+01:00", "+0100", or simply "+01".

Iran Standard Time time zone used in Iran

Iran Standard Time (IRST) or Iran Time (IT) is the time zone used in Iran. Iran uses a UTC offset UTC+03:30. IRST is defined by the 52.5 degrees east meridian, the same meridian which defines the Iranian calendar and is the official meridian of Iran.


Kujiki (旧事紀), or Sendai Kuji Hongi (先代旧事本紀), is a historical Japanese text. It was generally believed to have been one of the earliest Japanese histories until the middle of the Edo period, when scholars such as Tokugawa Mitsukuni successfully contended that it was an imitation based on the Nihon Shoki, the Kojiki and the Kogo Shūi. Scholarship on the Kujiki generally considers it to contain some genuine elements, specifically that Book 5 preserves traditions of the Mononobe and Owari clans, and that Book 10 preserves the earlier historical record the Kokuzō Hongi.

Time in Mexico

Mexico uses four main time zones since February 2015. Most of the country observes Daylight Saving Time.

  1. Zona Sureste covers the state of Quintana Roo is UTC-05:00 year round. It is the equivalent of U.S. Eastern Standard Time.
  2. Zona Centro covers the eastern three-fourths of Mexico, including Mexico City, Guadalajara and Monterrey. For most of the year, it is the equivalent of U.S. Central Time.
  3. Zona Pacífico covers the states of Baja California Sur, Chihuahua, Nayarit, Sinaloa, and Sonora. The state of Sonora, like the U.S. state of Arizona, does not observe daylight saving time. For most of the year, it is the equivalent of U.S. Pacific Time.
  4. Zona Noroeste covers the state of Baja California. It is identical to U.S. Pacific Time, including the daylight saving time schedule.
Time in North Korea zone time

Time in North Korea, called Pyongyang Time or Standard Time of the Democratic People's Republic of Korea, is since May 2018 equal to Korea Standard Time: 9 hours ahead of UTC (UTC+09:00). Like South Korea, North Korea does not currently observe daylight saving time. Time keeping in North Korea is under the State Commission for Science and Technology.

Time in Taiwan timezone of Taiwan

National Standard Time is the official time zone in Taiwan defined by an UTC offset of +08:00. This standard is also known as Taiwan Time (臺灣時間), Taipei Time (臺北時間) and historically as Chungyuan Standard Time (中原標準時間) until the early 2000s.

Road signs in Japan road signs used in Japan

In Japan, road signs are standardized by the "Order on Road Sign, Road Line, and Road Surface Marking (道路標識、区画線及び道路標示に関する命令)" established on 1968 whose origins are Tokyo Metropolitan Police Department's "Order on Standardization of Road Sign" on 1934 and Home Ministry of Japan's "Order on Road Signs" on 1942. The previous designs have been used since 1986 after several amendments of order.

The time zones of China refer to the time zone divisions used in China between 1918 and 1949. The first time zone plan was proposed by the Central Observatory of the Beiyang government in Peking (Beijing) in 1918. The proposal divided the country into five time zones: Kunlun (UTC+05:30), Sinkiang-Tibet (UTC+06:00), Kansu-Szechwan (UTC+07:00), Chungyuan (UTC+08:00) and Changpai (UTC+08:30). These time zones were ratified in 1939 by the Nationalist government in the Standard Time Conference, hosted by the Ministry of Interior of Executive Yuan. Because of the Second Sino-Japanese War, it was also stated that Kansu-Szechwan time shall be the sole national time during the war time. After the war in 1945, these five times zones were implemented national widely. In 1949, after the Chinese Civil War, the Central People's Government abolished the five time zones and announced to use a single time zone UTC+08:00 named Beijing Time (北京时间). The term Chungyuan Standard Time (中原標準時間) was still used by the Nationalist government on Taiwan until the early 2000s.

Time in Portugal

Portugal has two time zones and observes daylight saving time. Continental Portugal and Madeira use UTC+00:00, while the Azores use UTC–01:00. Daylight saving time is observed nationwide from the last Sunday in March to the last Sunday in October, so that every year, continental Portugal and Madeira temporarily use UTC+01:00, and the Azores temporarily use UTC+00:00.


  1. "Current Local Time in Japan". timeanddate.com.
  2. 明治十九年勅令第五十一号(本初子午線経度計算方及標準時ノ件)
    • 英国グリニツチ天文台子午儀ノ中心ヲ経過スル子午線ヲ以テ経度ノ本初子午線トス
    • 経度ハ本初子午線ヨリ起算シ東西各百八十度ニ至リ東経ヲ正トシ西経ヲ負トス
    • 明治二十一年一月一日ヨリ東経百三十五度ノ子午線ノ時ヲ以テ本邦一般ノ標準時ト定ム
  3. 明治二十八年勅令第百六十七號(標準時ニ關スル件) - Wikisource
  4. 昭和十二年勅令第五百二十九號(明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件) - Wikisource
  5. Paul Eggert; Arthur David Olson (2007-03-13). "Sources for time zone and daylight saving time data" . Retrieved 2007-03-23.
  6. "Outline of the report on the National Conference on the Global Environment and Summer Time". The Energy Conservation Center, Japan. September 1998. Archived from the original on 2007-04-09. Retrieved 2007-04-14.
  7. Hongo, Jun, "Daylight saving: Is it finally time to convert?", Japan Times , 28 June 2011, p. 3.
  8. https://www.japantimes.co.jp/news/2002/04/28/national/history/japans-long-awaited-spring/#.W-RKltJvb3g
  9. Hongo, Jun, "Daylight saving: Is it finally time to convert?", Japan Times , 28 June 2011, p. 3.
  10. Thousands in Japan Adopt “Daylight Saving” Plan
  11. "Panel to call for daylight saving time". Yomiuri Shimbun. 2007-06-02. Archived from the original on 2007-06-06. Retrieved 2007-06-02.
  12. Yoshiyuki Shimoda; Takahiro Asahia; Ayako Taniguchia; Minoru Mizuno. (2007). "Evaluation of city-scale impact of residential energy conservation measures using the detailed end-use simulation model". Energy. 32 (9): 1617–1633. doi:10.1016/j.energy.2007.01.007.