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Japan to HST

-19h

Japan

JSTSOURCE
UTC+09:00
HH12
:
MM00
  
12:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM

HST

HST
UTC-10:00
HH05
:
MM00
  
(previous day)17:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
Japan
HST
12:00 AM
5:00 AM-1
2:00 AM
7:00 AM-1
4:00 AM
9:00 AM-1
6:00 AM
11:00 AM-1
8:00 AM
1:00 PM-1
10:00 AM
3:00 PM-1
12:00 PM
5:00 PM-1
2:00 PM
7:00 PM-1
4:00 PM
9:00 PM-1
6:00 PM
11:00 PM-1
8:00 PM
1:00 AM
10:00 PM
3:00 AM

Green rows indicate typical business hours (9 AM - 5 PM)

JST and HST on the World Map

The map below highlights the JST (Japan Standard Time) and HST (Hawaii Standard Time) timezone regions across the globe.

JSTHSTTokyoOsakaYokohamaNagoyaHonoluluHiloKailuaPearl City
JST Zone
→
HST Zone

Explore all world timezones interactively →

JST – Japan Standard Time

UTC+09:00

Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.

Countries in JST
Japan
Major Cities in JST
TokyoOsakaYokohamaNagoyaSapporoKyotoKobeFukuokaHiroshima
Key Facts about JST
  • •Japan does not observe daylight saving time.
  • •Tokyo is the most populous metropolitan area in the world.
  • •The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
  • •JST is 14 hours ahead of EST and 9 hours ahead of GMT.
Daylight Saving:No – UTC+09:00 year-round
Learn more about JST on Wikipedia

HST – Hawaii Standard Time

UTC-10:00

Hawaii Standard Time (HST) is the time zone for the Hawaiian Islands, 10 hours behind UTC.

Countries in HST
United States (Hawaii)
Major Cities in HST
HonoluluHiloKailuaPearl CityKapolei
Key Facts about HST
  • •Hawaii does not observe daylight saving time.
  • •HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
  • •Hawaii is one of only two US states that don't observe DST (the other is Arizona).
Daylight Saving:No – UTC-10:00 year-round
Learn more about HST on Wikipedia

Comparing Time Zones: Japan and HST

Japan runs on Japan Standard Time (JST) at UTC+09:00. HST runs on Hawaii Standard Time (HST) at UTC-10:00. That puts Japan 19 hours behind HST — a difference of -19h at the current offsets.

In practice, when it is 9:00 AM in Japan it is 2:00 PM in HST on the previous day. Midnight in Japan is 5:00 AM in HST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Japan to HST time conversion table

Japan (JST)HST (HST)Day
12:00 AM5:00 AMprevious day
6:00 AM11:00 AMprevious day
7:00 AM12:00 PMprevious day
8:00 AM1:00 PMprevious day
9:00 AM2:00 PMprevious day
12:00 PM5:00 PMprevious day
3:00 PM8:00 PMprevious day
5:00 PM10:00 PMprevious day
6:00 PM11:00 PMprevious day
9:00 PM2:00 AMsame day

Why people convert Japan to HST time

  • Scheduling a call from Japan to HST: a 10:00 AM start in Japan lands at 3:00 PM in HST the previous day, so you can confirm the slot without doing the arithmetic yourself.
  • Handling a -19h gap: Japan and HST have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in HST is 2:00 PM in Japan.
  • Keeping family and friends in sync: knowing that 8:00 PM in Japan is 1:00 AM in HST makes it easy to avoid calling at 3 AM.
  • Always state the zone abbreviation, not just the hour. "3:00 PM JST" is unambiguous; "3 PM" across a -19h gap is not.
  • With a -19h gap there is no shared 9-to-5 window, so alternate the early start: one week Japan takes the early slot, the next week HST does.

About JST (Japan Standard Time)

Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.

About HST (Hawaii Standard Time)

Hawaii Standard Time (HST) is used in the state of Hawaii and does not observe daylight saving time. This makes HST one of the most consistent time zones in the US. The Hawaiian Islands are among the last places on Earth to see a new calendar day.

Best time to call between Japan and HST

With a -19h offset there is no overlap inside a normal 9 AM – 5 PM day. HST opens at 9:00 AM HST, which is 2:00 PM in Japan, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

Japan and HST have no shared working hours because of the -19h gap. Teams need to alternate early starts or rely on asynchronous handovers.

Japan is 19 hours behind HST (JST UTC+09:00 → HST UTC-10:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

Frequently Asked Questions

What is the time difference between Japan and HST?

Japan (JST, UTC+09:00) is 19 hours behind HST (HST, UTC-10:00). The gap is currently -19h.

How do I convert Japan time to HST time?

Add -19h to Japan local time. For example, 9:00 AM in Japan is 2:00 PM in HST (previous day).

What time is it in HST right now?

HST uses HST at UTC-10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -19h offset from Japan.

What is the best time to call HST from Japan?

There is no shared working-hours window because of the -19h gap. The closest option is 1:00 PM in Japan, which is 6:00 PM in HST.

Which is behind, Japan or HST?

Japan is 19 hours behind HST. When it is 12:00 PM in Japan it is 5:00 PM in HST.

Do Japan and HST use different time zones?

Japan (Japan) uses JST at UTC+09:00, while HST uses HST at UTC-10:00. The IANA identifiers are Asia/Tokyo and Pacific/Honolulu.

Does daylight saving time affect the Japan–HST difference?

Neither zone observes daylight saving time, so the -19h offset between Japan and HST is fixed all year.

Which other cities share Japan's time zone?

JST also covers Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Kobe, Fukuoka and 1 more.

Which countries use JST, Japan's zone?

JST is used in Japan.

Is there a day difference between Japan and HST?

Sometimes. The -19h gap is large enough that 8:00 PM or later in Japan already falls on the in HST.

What is the time difference between Japan and HST?

HST is -19h from Japan.

What timezone is Japan in?

Japan operates on its local timezone.

What timezone is HST in?

HST operates on its local timezone.

Which countries use JST (Japan Standard Time)?

JST is used in Japan.

Does JST observe daylight saving time?

No, JST does not observe daylight saving time and remains at UTC+09:00 year-round.

What are some interesting facts about JST?

Japan does not observe daylight saving time. Tokyo is the most populous metropolitan area in the world.

Which cities are in the HST timezone?

Major cities in the HST timezone include Honolulu, Hilo, Kailua, Pearl City, Kapolei.

What is the UTC offset for HST?

Hawaii Standard Time (HST) is at UTC-10:00.

What should I know about the HST timezone?

Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.

When is it midnight in Japan, what time is it in HST?

When it is 12:00 AM (midnight) in Japan (JST), it is -19h later in HST (HST).