, or , is the standard
time zone
A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...
in
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
, 9 hours ahead of UTC (
UTC+09:00). Japan does not observe daylight saving time, though its introduction has been debated on several occasions. During
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, 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 Korea, Korean Peninsula and borders China and Russia to the north at the Yalu River, Yalu (Amnok) an ...
),
Eastern Indonesia Standard Time,
East-Timorese Standard Time,
Palau Time, and
Yakutsk Time (
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
).
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
In observational astronomy, culmination is the passage of a celestial object (such as the Sun, the Moon, a planet, a star, constellation or a deep-sky object) across the observer's local meridian. These events are also known as meridian tran ...
. 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, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...
and
Osaka
is a Cities designated by government ordinance of Japan, designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the List of cities in Japan, third-most populous city in J ...
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 a Prefectures of Japan, prefecture of Japan located in the Kansai region of Honshu. Hyōgo Prefecture has a population of 5,469,762 () and a geographic area of . Hyōgo Prefecture borders Kyoto Prefecture to the east, Osaka Prefecture to th ...
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
The Penghu ( , Hokkien POJ: ''Phîⁿ-ô͘'' or ''Phêⁿ-ô͘'' ) or Pescadores Islands are an archipelago of 90 islands and islets in the Taiwan Strait, about west of the main island of Taiwan across the Penghu Channel, cove ...
. While
Korea
Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...
came
under Japanese rule in 1910,
Korea Standard Time
South Korea has one time zone, Korea Standard Time (UTC+09:00, UTC+9), which is abbreviated KST. South Korea currently does not observe daylight saving time.
From May 8 to October 9 in 1988, daylight saving time was tested to better accommodat ...
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. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
and some parts of
Okinawa, 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 an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...
and
Malaya, 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, 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, ...
(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 contains one zone for Japan in the file
zone.tab, 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 (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
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 the list of islands of Japan by area, second-largest island of Japan 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 fr ...
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
The Cabinet Office is a Departments of the Government of the United Kingdom, ministerial department of the Government of the United Kingdom. It is responsible for supporting the Prime Minister of the United Kingdom, prime minister and Cabinet ...
is expected
(written October 2013) to propose that the Japanese government begin studying DST in an attempt to help combat
global warming
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...
.
Japanese former 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 in Japan. A 2007 simulation estimated that introducing DST to Japan would increase energy use in
Osaka
is a Cities designated by government ordinance of Japan, designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the List of cities in Japan, third-most populous city in J ...
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.
Possibility of adjusting the time zone
On May 22, 2013,
Governor of Tokyo Naoki Inose proposed a two-hour advance (
UTC+11) Japan Standard Time at an industry competitiveness conference. Its purpose is to enhance the influence of the
Japanese financial market by starting early in the
Tokyo financial market. The Japanese government has decided to consider this proposal.
However, there has been no specific discussion of this proposal for more than ten years.
See also
*
Japanese calendar
Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the Japanese era name, year of the reign of the current Emperor. The written f ...
*
Japanese clock
*
JJY
*
UTC+09:00
References
External links
*
What time is it in Japan? Understand Japanese TimeCurrent Time in Japan
{{Asia topic, Time in
Time in Japan
Time zones