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South Korea to Honolulu

-19h

South Korea

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

Honolulu

HST
USA · UTC-10:00
HH05
:
MM00
  
(previous day)17:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
South Korea
Honolulu
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)

KST and HST on the World Map

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

KSTHSTSeoulBusanIncheonDaeguHonoluluHiloKailuaPearl City
KST Zone
→
HST Zone

Explore all world timezones interactively →

KST – Korea Standard Time

UTC+09:00

Korea Standard Time (KST) is the time zone for South Korea, 9 hours ahead of UTC.

Countries in KST
South KoreaNorth Korea
Major Cities in KST
SeoulBusanIncheonDaeguDaejeonPyongyang
Key Facts about KST
  • •South Korea does not observe daylight saving time.
  • •Seoul is home to Samsung, LG, and Hyundai headquarters.
  • •KST is the same offset as JST (UTC+09:00).
Daylight Saving:No – UTC+09:00 year-round
Learn more about KST 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

About Honolulu

Wikipedia

Honolulu operates on Hawaii Standard Time (HST), UTC-10 with no daylight saving. Hawaii's consistent time makes it a predictable connection between Asia and mainland USA.

Population:350,000
Metro:1 million
Business Hours:8:00 AM - 5:00 PM HST
Currency:USD ($)
Key Landmarks
Waikiki BeachDiamond HeadPearl HarborIolani PalaceHanauma Bay
Did You Know?

Pearl Harbor memorial receives over 2 million visitors annually.

Learn more about HST timezone →

South Korea vs Honolulu: Offsets, DST and Best Call Times

South Korea runs on Korean Standard Time (KST) at UTC+09:00. Honolulu runs on Hawaii-Aleutian Standard Time (HST) at UTC-10:00. That puts South Korea 19 hours behind Honolulu — a difference of -19h at the current offsets.

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

South Korea to Honolulu time conversion table

South Korea (KST)Honolulu (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 South Korea to Honolulu time

  • Scheduling a call from South Korea to Honolulu: a 10:00 AM start in South Korea lands at 3:00 PM in Honolulu the previous day, so you can confirm the slot without doing the arithmetic yourself.
  • Handling a -19h gap: South Korea and Honolulu 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 Honolulu is 2:00 PM in South Korea.
  • Coordinating a South Korea-based team with Honolulu contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
  • Always state the zone abbreviation, not just the hour. "3:00 PM KST" 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 South Korea takes the early slot, the next week Honolulu does.

About KST (Korea Standard Time)

Korea Standard Time (KST) is the time zone used in South Korea. It shares the same UTC offset as Japan Standard Time but is a distinct time zone. South Korea does not observe daylight saving time. Seoul, the capital, is a major global tech and business hub.

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 South Korea and Honolulu

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

Business hours overlap

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

South Korea is 19 hours behind Honolulu (KST 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 South Korea and Honolulu?

South Korea (KST, UTC+09:00) is 19 hours behind Honolulu (HST, UTC-10:00). The gap is currently -19h.

How do I convert South Korea time to Honolulu time?

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

What time is it in Honolulu right now?

Honolulu 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 South Korea.

What is the best time to call Honolulu from South Korea?

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

Which is behind, South Korea or Honolulu?

South Korea is 19 hours behind Honolulu. When it is 12:00 PM in South Korea it is 5:00 PM in Honolulu.

Do South Korea and Honolulu use different time zones?

South Korea (South Korea) uses KST at UTC+09:00, while Honolulu (USA) uses HST at UTC-10:00. The IANA identifiers are Asia/Seoul and Pacific/Honolulu.

Does daylight saving time affect the South Korea–Honolulu difference?

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

Which other cities share South Korea's time zone?

KST also covers Seoul, Busan, Incheon, Daegu, Daejeon, Pyongyang.

Which countries use KST, South Korea's zone?

KST is used in South Korea, North Korea.

Is there a day difference between South Korea and Honolulu?

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

What is the time difference between South Korea and Honolulu?

Honolulu is -19h from South Korea.

What timezone is South Korea in?

South Korea operates on its local timezone.

What timezone is Honolulu in?

Honolulu operates on Hawaii Standard Time (HST), UTC-10 with no daylight saving. Hawaii's consistent time makes it a predictable connection between Asia and mainland USA.

What are the business hours in Honolulu?

Standard business hours in Honolulu are 8:00 AM - 5:00 PM HST.

Which countries use KST (Korea Standard Time)?

KST is used in South Korea, North Korea.

Does KST observe daylight saving time?

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

What are some interesting facts about KST?

South Korea does not observe daylight saving time. Seoul is home to Samsung, LG, and Hyundai headquarters.

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 South Korea, what time is it in Honolulu?

When it is 12:00 AM (midnight) in South Korea (KST), it is -19h later in Honolulu (HST).