Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

Singapore to Honolulu

-18h

Singapore

SGTSOURCE

Singapore · UTC+08:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Honolulu

HST

USA · UTC-10:00

HH06

MM00

(previous day)18:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Singapore

Honolulu

12:00 AM

6:00 AM-1

2:00 AM

8:00 AM-1

4:00 AM

10:00 AM-1

6:00 AM

12:00 PM-1

8:00 AM

2:00 PM-1

10:00 AM

4:00 PM-1

12:00 PM

6:00 PM-1

2:00 PM

8:00 PM-1

4:00 PM

10:00 PM-1

6:00 PM

12:00 AM

8:00 PM

2:00 AM

10:00 PM

4:00 AM

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

SGT and HST on the World Map

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

SGT Zone

→

HST Zone

Explore all world timezones interactively →

SGT – Singapore Standard Time

UTC+08:00

Singapore Standard Time (SGT) is the time zone for Singapore, 8 hours ahead of UTC.

Countries in SGT

Singapore

Major Cities in SGT

Singapore

Key Facts about SGT

•Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00).
•Singapore does not observe daylight saving time.
•The Singapore Exchange (SGX) operates on SGT.

Daylight Saving:No – UTC+08:00 year-round

Learn more about SGT 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 Singapore

Wikipedia

Singapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.

Population:5.5 million

Metro:5.9 million

Business Hours:9:00 AM - 6:00 PM SGT

Currency:SGD (S$)

Stock Exchange:SGX (Singapore Exchange)

Key Landmarks

Marina Bay SandsGardens by the BayMerlionSentosa IslandOrchard Road

Did You Know?

The city-state has the world's highest percentage of millionaires, with 1 in 6 households.

Learn more about SGT timezone →

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 →

Understanding the -18h Gap: Singapore vs Honolulu

Singapore runs on Singapore Standard Time (SGT) at UTC+08:00. Honolulu runs on Hawaii-Aleutian Standard Time (HST) at UTC-10:00. That puts Singapore 18 hours behind Honolulu — a difference of -18h at the current offsets.

In practice, when it is 9:00 AM in Singapore it is 3:00 PM in Honolulu on the previous day. Midnight in Singapore is 6:00 AM in Honolulu. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Singapore to Honolulu time conversion table

Singapore (SGT)	Honolulu (HST)	Day
12:00 AM	6:00 AM	previous day
6:00 AM	12:00 PM	previous day
7:00 AM	1:00 PM	previous day
8:00 AM	2:00 PM	previous day
9:00 AM	3:00 PM	previous day
12:00 PM	6:00 PM	previous day
3:00 PM	9:00 PM	previous day
5:00 PM	11:00 PM	previous day
6:00 PM	12:00 AM	same day
9:00 PM	3:00 AM	same day

Why people convert Singapore to Honolulu time

Scheduling a call from Singapore to Honolulu: a 10:00 AM start in Singapore lands at 4:00 PM in Honolulu the previous day, so you can confirm the slot without doing the arithmetic yourself.
Handling a -18h gap: Singapore 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 3:00 PM in Singapore.
Keeping family and friends in sync: knowing that 8:00 PM in Singapore is 2:00 AM in Honolulu makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM SGT" is unambiguous; "3 PM" across a -18h gap is not.
With a -18h gap there is no shared 9-to-5 window, so alternate the early start: one week Singapore takes the early slot, the next week Honolulu does.

About SGT (Singapore Standard Time)

Singapore Standard Time (SGT) is used in Singapore year-round. Singapore does not observe daylight saving time. Despite being geographically close to the UTC+07:00 zone, Singapore uses UTC+08:00 to align with major trading partners like China, Hong Kong, and Malaysia. Singapore is a major global financial 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 Singapore and Honolulu

With a -18h offset there is no overlap inside a normal 9 AM – 5 PM day. Honolulu opens at 9:00 AM HST, which is 3:00 PM in Singapore, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

Singapore and Honolulu have no shared working hours because of the -18h gap. Teams need to alternate early starts or rely on asynchronous handovers.

Singapore is 18 hours behind Honolulu (SGT UTC+08:00 → 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.

Learn More About Time

Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between Singapore and Honolulu?

Singapore (SGT, UTC+08:00) is 18 hours behind Honolulu (HST, UTC-10:00). The gap is currently -18h.

How do I convert Singapore time to Honolulu time?

Add -18h to Singapore local time. For example, 9:00 AM in Singapore is 3:00 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 -18h offset from Singapore.

What is the best time to call Honolulu from Singapore?

There is no shared working-hours window because of the -18h gap. The closest option is 1:00 PM in Singapore, which is 7:00 PM in Honolulu.

Which is behind, Singapore or Honolulu?

Singapore is 18 hours behind Honolulu. When it is 12:00 PM in Singapore it is 6:00 PM in Honolulu.

Do Singapore and Honolulu use different time zones?

Singapore (Singapore) uses SGT at UTC+08:00, while Honolulu (USA) uses HST at UTC-10:00. The IANA identifiers are Asia/Singapore and Pacific/Honolulu.

Does daylight saving time affect the Singapore–Honolulu difference?

Neither zone observes daylight saving time, so the -18h offset between Singapore and Honolulu is fixed all year.

Which other cities share Singapore's time zone?

SGT also covers Singapore.

Which countries use SGT, Singapore's zone?

SGT is used in Singapore.

Is there a day difference between Singapore and Honolulu?

Sometimes. The -18h gap is large enough that 8:00 PM or later in Singapore already falls on the in Honolulu.

What is the time difference between Singapore and Honolulu?

Honolulu is -18h from Singapore.

What timezone is Singapore in?

Singapore Standard Time (SGT) is 8 hours ahead of GMT. As Asia's leading financial hub, Singapore bridges business hours between Europe and Australia.

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 Singapore?

Standard business hours in Singapore are 9:00 AM - 6:00 PM SGT.

What are the business hours in Honolulu?

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

What is the best time to schedule a call between Singapore and Honolulu?

The best overlap for a call is when both cities are in business hours. Singapore works 9:00 AM - 6:00 PM SGT and Honolulu works 8:00 AM - 5:00 PM HST (-18h difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Singapore and Honolulu?

Singapore uses SGD (S$) while Honolulu uses USD ($). Check current exchange rates when planning travel or business between these cities.

How do Singapore and Honolulu compare in size?

Singapore has a population of approximately 5.5 million (metro: 5.9 million), while Honolulu has approximately 350,000 (metro: 1 million).

What are the major landmarks in Singapore and Honolulu?

Singapore is known for Marina Bay Sands, Gardens by the Bay, Merlion. Honolulu is famous for Waikiki Beach, Diamond Head, Pearl Harbor.

Do Singapore and Honolulu have stock exchanges?

Yes. Singapore has the SGX (Singapore Exchange) and Honolulu has the N/A (Uses NYSE/NASDAQ). The -18h time difference affects trading hour overlaps between these exchanges.