Japan Standard Time: One Time Zone, No Daylight Saving and the Akashi Meridian

Learn how Japan Standard Time works, why the whole country shares one clock without daylight saving, and what the Akashi meridian has to do with it.

Published October 20, 2026 at 11:19 AM JST | By Tokyo Paul

Quick answer: Japan Standard Time (JST) is nine hours ahead of Coordinated Universal Time (UTC+9). The whole country, from Hokkaido to Okinawa, uses this single time zone. Japan does not currently use daylight saving time. The standard meridian is 135 degrees east, which passes through the city of Akashi in Hyogo Prefecture, and the National Institute of Information and Communications Technology maintains the official time.

What Japan Standard Time means

Japan Standard Time, usually shortened to JST, is the official clock time used across Japan. It runs nine hours ahead of Coordinated Universal Time, the global reference that replaced the older Greenwich Mean Time as the basis for civil time. In written form it appears as UTC+9 or UTC+09:00.

For a traveler, the practical meaning is simple. A train timetable in Sapporo, a museum schedule in Kyoto and a ferry departure in Okinawa all use the same hour. There is no need to ask which time zone a listing uses, and there is no seasonal clock change to remember when planning a trip.

One time zone for the whole country

Japan stretches a long way from northeast to southwest, yet it keeps one national time. Hokkaido in the far north, the main island of Honshu, Kyushu and the Okinawa islands in the subtropical south all run on JST. When it is noon in Tokyo, it is noon everywhere else in the country.

This makes itineraries easy to build. A flight that leaves Naha at a stated time and lands in Tokyo is measured on the same clock at both ends, so the printed duration matches the difference between the two times. Long-distance trains and domestic flights follow the same logic.

Japan once used more than one standard time. A western standard time set at 120 degrees east was created in 1895 for some outlying areas, and it was abolished in 1937. Today the single zone is the rule everywhere in the country.

The Akashi meridian at 135 degrees east

Standard time is tied to a line of longitude, and for Japan that line is 135 degrees east. The city of Akashi, in Hyogo Prefecture on the coast of the Seto Inland Sea, sits on this meridian. Because of that, Akashi is often called Toki no machi, the Town of Time.

The Akashi Municipal Planetarium stands on the 135 degree line, which is the best-known landmark connected with the national clock. The city is also known for its castle and its fish market, so a stop can fit naturally into a day trip from Kobe or Osaka. Akashi's official visitor pages are the best place to check what is currently open and how to reach the site.

The numbers fit together neatly. The earth turns 15 degrees of longitude for each hour, so a meridian 135 degrees east of Greenwich lines up with a clock nine hours ahead, which is exactly the UTC+9 offset Japan uses today.

A short history of standard time in Japan

Before standard time, towns kept time by the sun, so local noon differed a little from place to place. Railways and telegraph networks made a shared clock useful, and the government addressed it by ordinance. Ordinance 51, dated 13 July 1886, named 135 degrees east as the standard meridian for the country, and it took effect on 1 January 1888.

Tokyo and Osaka lie about 5 degrees of longitude apart, so local solar time differs by roughly 20 minutes between them, which shows why one agreed clock was easier than each town keeping its own time. In 1895 a further ordinance renamed the national time Central Standard Time and created the separate Western Standard Time mentioned above.

Since then the central clock has stayed in place. The name Japan Standard Time is now the everyday term, and the National Institute of Information and Communications Technology (NICT) maintains it and keeps it closely aligned with UTC.

Why daylight saving is not used

Daylight saving time moves clocks forward in warmer months. Japan tried it for a few summers during the Allied occupation after the Second World War, starting in 1948. Published accounts differ on whether the last summer was 1951 or 1952, and the system was dropped around the end of the occupation. It has not been applied nationwide since.

The idea has returned to the conversation from time to time. A Cabinet Office council considered reintroducing it in 2007 as an environmental measure, though the effort did not succeed, and in 2013 the Tokyo governor floated moving the country two hours ahead to UTC+11. As things stand, clocks in Japan stay the same all year.

For visitors, this means nothing to change in spring or autumn. Phones, hotel clocks and station displays keep the same hour in January and July. Rules can be reviewed at any time, so a quick look at an official source is worthwhile if a trip is far in the future.

Official time and the NICT signal

The official national time is generated, compared and distributed by NICT, whose JST Group also handles the national frequency standard. The institute offers time services over the internet, and a long-wave radio signal known as JJY carries standard time and frequency information. Radio-controlled clocks and watches in Japan can set themselves from this signal.

NICT's English homepage lists news about the time service, though some details about the transmitting stations are published only in Japanese. Most travelers never need more than a phone that syncs automatically, but the existence of a public time service explains why station clocks and train departures line up so closely.

Anyone who relies on a particular method, such as a radio-controlled watch or a network time server, should check NICT's pages for current notices. Transmitting stations and servers are maintained from time to time, and the institute publishes announcements about those changes, so the official page is the dependable place to look before a trip or a project that depends on exact timing.

Sunrise, jet lag and planning tips

One time zone does not mean one sunrise. Because Japan covers many degrees of longitude and latitude, the sun rises earlier in the east and north than in the southwest. Because the clock is shared, the sun reaches places in the far east of the country earlier on the clock than places in the far west. Day length also changes with latitude and season, so exact sunrise and sunset times depend on the date and place, and a sunrise table for the chosen city is the right tool.

Comparing time with home is easy to do in advance. Because Japan is fixed at UTC+9 all year, the gap with home changes only when the home country changes its own clocks. A time zone converter or the phone's world clock shows the current difference for any date, which is worth checking when booking calls, flights or tours near the spring and autumn clock changes abroad.

Common advice for adjusting includes getting daylight in the morning at the destination, keeping the first day light, and drinking water. This guide shares general information; rules change, so confirm details with the official agency or provider before you act.

Frequently Asked Questions

What time zone does Japan use?

Japan uses Japan Standard Time, which is UTC+9. The same time applies in every part of the country, including Hokkaido, Honshu, Kyushu, Shikoku and Okinawa. There is no separate regional time, so a schedule printed anywhere in Japan uses the same clock.

Does Japan have daylight saving time?

No. Japan does not currently use daylight saving time. It was tried during the occupation period after the Second World War and then dropped around 1952. Discussions have come up since, including a Cabinet Office council in 2007, but clocks do not change in spring or autumn.

Why is Akashi important for Japan's time?

Akashi in Hyogo Prefecture lies on the 135 degrees east meridian, which is the standard meridian for Japan Standard Time. The city is known as the Town of Time, and its planetarium stands on the line. It is an easy stop from Kobe or Osaka.

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