, or , is the standard
time zone
A time zone is an area which observes a uniform standard time for legal, commercial and social purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude, because i ...
in
Japan, 9 hours ahead of UTC (
UTC+09:00). Japan does not observe
daylight saving time
Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typical ...
, though its introduction has been debated on several occasions. During
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
, the time zone was often referred to as Tokyo Standard Time.
Japan Standard Time is equivalent to
Korean Standard Time,
Pyongyang Time (
North Korea
North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and ...
),
Eastern Indonesia Standard Time,
East-Timorese Standard Time and
Yakutsk Time (
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...
).
History
Before the
Meiji era (1868–1912), each local region had its own time zone in which noon was when the sun was exactly at its
culmination. 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
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and List of cities in Japan, largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, ...
and
Osaka
is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of ...
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:
According to this, the 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 time zone 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).
With the
annexation of Taiwan in 1895, Ordinance 167 (pictured on the right) was issued to rename the previous Standard Time to and establish a new at
120° longitude as the time zone for the Japanese
Miyako and
Yaeyama Islands, as well as Taiwan and its
Penghu Islands. While
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republi ...
came
under Japanese rule in 1910,
Korea Standard Time of GMT+08:30 continued to be used until 1912, when it was changed to Central Standard Time.
Western Standard Time, which was used in
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northe ...
and some parts of
Okinawa
is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi).
Naha is the capital and largest city ...
, was abolished by Ordinance 529 in 1937 and replaced by Central Standard Time in those areas. Territories occupied by Japan during World War II, including
Singapore
Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
and
Malaya
Malaya refers to a number of historical and current political entities related to what is currently Peninsular Malaysia in Southeast Asia:
Political entities
* British Malaya (1826–1957), a loose collection of the British colony of the Straits ...
, adopted Japan Standard Time for the duration of their occupation, but reverted after
Japan's surrender.
Between 1948 and 1951
occupied Japan observed
daylight saving time
Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typical ...
(DST) from the first Saturday in May at 24:00 to the second Saturday in September at 24:00 (with the exception of 1949, when the spring forward transition was the first Saturday in April at 24:00). More recently there have been efforts to restore daylight saving time in Japan but these have not succeeded.
In May 2013, former Tokyo governor
Naoki Inose proposed permanently moving the country’s time zone ahead by 2 hours to better align global markets and make Japan’s stock market to be the first to open in the world at any given time.
Time zones of the Japanese Empire
The two-time-zone system was implemented in Japan between January 1896 and September 1937:
From October 1937, Central Standard Time was also used in western Okinawa and Taiwan.
IANA time zone database
The
IANA time zone database
The tz database is a collaborative compilation of information about the world's time zones, primarily intended for use with computer programs and operating systems. Paul Eggert is its current editor and maintainer, with the organizational back ...
contains one zone for Japan in the file
zone.tab
This is a list of time zones from release of the tz database.
Legend Type
* Canonical - The primary, preferred zone name.
* Link - An alternative name (alias) which links to a canonical zone.
* Link - A standard Link (as above). The dagger symb ...
, named Asia/Tokyo.
Daylight saving time in Japan
From 1948 to 1952, Japan observed daylight saving time (DST) between May and September every year. The
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
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 saving time, and the Allied occupation authorities did not interfere. Since then, DST has never been officially implemented nationwide in Japan.
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
is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; th ...
region is particularly in favour 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 shortly 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 26 June to 1 July, despite being at 35°41'N latitude). Since 2000, a few local governments and commerce departments have promoted unmandated hour-earlier work schedule experiments during the summer without officially resetting clocks.
The Council on Economic and Fiscal Policy of the
Cabinet Office is expected
(written October 2013) to propose that the Japanese government begin studying DST in an attempt to help combat
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes ...
.
Japanese Prime Minister Shinzō Abe made a significant effort to introduce daylight saving time, but was ultimately unsuccessful. However, it is not clear that DST would
conserve energy
Energy conservation is the effort to reduce wasteful energy consumption by using fewer energy services. This can be done by using energy more effectively (using less energy for continuous service) or changing one's behavior to use less service (f ...
in Japan. A 2007 simulation estimated that introducing DST to Japan would increase energy use in
Osaka
is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of ...
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.
See also
*
Japanese calendar
*
Japanese clock
*
JJY
*
UTC+09:00
References
External links
*
{{Asia topic, Time in
Time in Japan
Time zones