Japan Standard Time

• 1. Introduction

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  Japan Standard Time sits exactly 9 hours ahead of UTC, a fixed, unwavering position that has not shifted by a single minute since 1888. While most of the world jolts its clocks forward and back with the seasons, Japan holds firm. No daylight saving time. No spring forward, no fall back. That steadiness is not an accident. It is the product of a deliberate, century-old choice, and the story behind it runs from a shogunate-era Japan with dozens of competing local noons, through the machinery of empire, through an American occupation that briefly forced Tokyo's hand, and all the way to a 2013 proposal that would have made Japan the first stock market to open each morning anywhere on earth. How did a nation sort out its clocks? And why, when almost everyone else bent to summer time, did Japan refuse?

• 2. Trains and the Problem of Local Noon

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  Before the Meiji era began in 1868, every region in Japan kept its own time. Noon arrived whenever the sun reached its highest point overhead, which varied from place to place depending on longitude. That arrangement worked well enough when travel was slow. Trains changed everything. Tokyo and Osaka sit about 5 degrees of longitude apart. A train leaving Tokyo would roll into Osaka 20 minutes behind Tokyo's clocks, creating confusion on every departure board in the country. The government's answer came in 1886 with Ordinance 51, issued on the 13th of July of that year. The ordinance ran to just three clauses. The first acknowledged that the prime meridian passes through England's Greenwich Observatory. The second defined east and west longitude. The third declared that, starting on the 1st of January 1888, the 135th degree of east longitude would serve as Japan's single standard meridian. The city of Akashi, in Hyogo Prefecture, sits precisely on that line. Akashi subsequently earned the local nickname Toki no machi, meaning Town of Time.

• 3. Empire and Multiple Clocks

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  The annexation of Taiwan in 1895 forced a second reckoning. A single meridian could not comfortably serve territories sprawling far to the west. Ordinance 167 was issued to handle the situation, renaming the existing standard and carving out a new, slower zone set at 120 degrees east longitude. That western zone covered the Miyako and Yaeyama islands, Taiwan, and Taiwan's Penghu Islands. Korea came under Japanese rule in 1910, but Korean Standard Time, then pegged at GMT+08:30, was left in place until 1912, when it was shifted to match what was then called Central Standard Time. The two-zone system ran from January 1896 through September 1937, with Central Standard Time covering the Japanese mainland and Korea, and Western Standard Time covering western Okinawa and Taiwan. Ordinance 529, issued in 1937, abolished the western zone entirely, folding those territories into Central Standard Time. Territories occupied during World War II, including Singapore and Malaya, were also pulled onto Japan Standard Time for the duration of the occupation, then reverted once Japan surrendered.

• 4. The American Interlude

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  From 1948 to 1951, occupied Japan observed daylight saving time, and the policy did not originate in Tokyo. The United States imposed it as part of the Allied occupation. Each year the clocks moved forward on the first Saturday in May at 24:00 and back on the second Saturday in September at 24:00, with one exception: in 1949, the spring transition fell on the first Saturday in April instead. In 1952, three weeks before the occupation formally ended, the Japanese government, which had by then been granted expanded powers, abolished daylight saving time. The Allied occupation authorities chose not to interfere. Japan has not observed DST nationwide since that moment.

• 5. The Daylight Saving Debate

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  Starting in the late 1990s, pressure to bring back DST mounted again. Proponents argued it would save energy and extend recreational hours in the evening. The Hokkaido region led the push. Because of its high latitude and its position near the eastern edge of the time zone, summer daylight in Hokkaido begins as early as 03:30 under standard time. Much of Hokkaido's solar time actually aligns closer to UTC+10:00 than to the official UTC+09:00. The sun in Tokyo, which sits at 35 degrees 41 minutes north latitude, sets at 19:01 at its latest, between the 26th of June and the 1st of July. In 2007, former Prime Minister Shinzo Abe led an effort through the Council on Economic and Fiscal Policy of the Cabinet Office to reinstate DST as a tool against global warming. That effort failed. A simulation from the same year estimated that introducing DST would actually increase energy use in Osaka residences by 0.13 percent: a 0.02 percent saving from reduced lighting costs would be more than offset by a 0.15 percent rise in cooling costs. The simulation covered only residential buildings. Since 2000, some local governments and commerce departments have quietly run experiments in which workers shift their schedules an hour earlier in summer without formally resetting any clocks.

• 6. A Proposal to Leap Ahead

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  On the 22nd of May 2013, Naoki Inose, then governor of Tokyo, stood before an industry competitiveness conference and proposed moving Japan's clocks forward by two full hours, to UTC+11. The argument was financial. At UTC+11, Tokyo's stock market would open before any other major exchange in the world each morning. The Japanese government agreed to consider the proposal. More than ten years later, no specific discussion has taken place, and Japan Standard Time remains exactly where Ordinance 51 set it in 1886: nine hours ahead of Greenwich, anchored to the 135th meridian, with Akashi quietly keeping its title as the Town of Time.