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).

HST to United Kingdom

+11h

HST

HSTSOURCE

UTC-10:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

United Kingdom

BST

UTC+01:00☀ DST active

HH11

MM00

23:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

HST

United Kingdom

12:00 AM

11:00 AM

2:00 AM

1:00 PM

4:00 AM

3:00 PM

6:00 AM

5:00 PM

8:00 AM

7:00 PM

10:00 AM

9:00 PM

12:00 PM

11:00 PM

2:00 PM

1:00 AM+1

4:00 PM

3:00 AM+1

6:00 PM

5:00 AM+1

8:00 PM

7:00 AM+1

10:00 PM

9:00 AM+1

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

HST and BST on the World Map

The map below highlights the HST (Hawaii Standard Time) and BST (Greenwich Mean Time) timezone regions across the globe.

HST Zone

→

BST Zone

Explore all world timezones interactively →

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

GMT – Greenwich Mean Time

UTC+00:00

Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.

Countries in GMT

United KingdomIrelandIcelandPortugal (mainland)GhanaSenegalMaliMauritaniaGambiaGuineaSierra LeoneLiberiaIvory CoastBurkina FasoMorocco (historically)

Major Cities in GMT

LondonDublinLisbonAccraReykjavikEdinburghCasablancaDakarBamakoAbidjanConakryFreetownMonrovia

Key Facts about GMT

•GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
•The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
•GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
•Iceland uses GMT year-round and never observes daylight saving time.
•The UK switches from GMT to BST (British Summer Time) in late March each year.

Daylight Saving:Yes – switches to BST

Learn more about GMT on Wikipedia

Everything You Need to Know About HST and United Kingdom Time

HST runs on Hawaii Standard Time (HST) at UTC-10:00. United Kingdom runs on British Summer Time (BST) at UTC+01:00, also currently on daylight saving time. That puts HST 11 hours ahead of United Kingdom — a difference of +11h at the current offsets.

In practice, when it is 9:00 AM in HST it is 8:00 PM in United Kingdom. Midnight in HST is 11:00 AM in United Kingdom.United Kingdom observes daylight saving time while HST does not, so the gap narrows or widens by an hour part of the year.

HST to United Kingdom time conversion table

HST (HST)	United Kingdom (BST)	Day
12:00 AM	11:00 AM	same day
6:00 AM	5:00 PM	same day
7:00 AM	6:00 PM	same day
8:00 AM	7:00 PM	same day
9:00 AM	8:00 PM	same day
12:00 PM	11:00 PM	same day
3:00 PM	2:00 AM	next day
5:00 PM	4:00 AM	next day
6:00 PM	5:00 AM	next day
9:00 PM	8:00 AM	next day

Why people convert HST to United Kingdom time

Scheduling a call from HST to United Kingdom: a 10:00 AM start in HST lands at 9:00 PM in United Kingdom, so you can confirm the slot without doing the arithmetic yourself.
Handling a +11h gap: HST and United Kingdom 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 United Kingdom is 8:00 PM in HST.
Coordinating a HST-based team with United Kingdom 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 HST" is unambiguous; "3 PM" across a +11h gap is not.
With a +11h gap there is no shared 9-to-5 window, so alternate the early start: one week HST takes the early slot, the next week United Kingdom does.
United Kingdom: Clocks fall back on Sun, Oct 25, 2026. Any meeting series spanning that date will shift by an hour in local time.

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.

About GMT (Greenwich Mean Time)

Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.

Best time to call between HST and United Kingdom

With a +11h offset there is no overlap inside a normal 9 AM – 5 PM day. United Kingdom opens at 9:00 AM BST, which is 8:00 PM in HST, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

HST and United Kingdom have no shared working hours because of the +11h gap. Teams need to alternate early starts or rely on asynchronous handovers.

HST is 11 hours ahead of United Kingdom (HST UTC-10:00 → BST UTC+01:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

HST

Does not observe DST

United Kingdom

☀ Currently in DST

Standard: UTC+00:00 · DST: UTC+01:00

Clocks fall back on Sun, Oct 25, 2026

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 HST and United Kingdom?

HST (HST, UTC-10:00) is 11 hours ahead of United Kingdom (BST, UTC+01:00). The gap is currently +11h.

How do I convert HST time to United Kingdom time?

Add +11h to HST local time. For example, 9:00 AM in HST is 8:00 PM in United Kingdom.

What time is it in United Kingdom right now?

United Kingdom uses BST at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +11h offset from HST.

What is the best time to call United Kingdom from HST?

There is no shared working-hours window because of the +11h gap. The closest option is 1:00 PM in HST, which is 12:00 AM in United Kingdom.

Which is ahead, HST or United Kingdom?

HST is 11 hours ahead of United Kingdom. When it is 12:00 PM in HST it is 11:00 PM in United Kingdom.

Do HST and United Kingdom use different time zones?

HST uses HST at UTC-10:00, while United Kingdom (United Kingdom) uses BST at UTC+01:00. The IANA identifiers are Pacific/Honolulu and Europe/London.

Does daylight saving time affect the HST–United Kingdom difference?

Yes at the moment: United Kingdom is on daylight saving time and HST is not, so the +11h gap shifts by an hour when exactly one of them changes clocks.

Which other cities share HST's time zone?

HST also covers Honolulu, Hilo, Kailua, Pearl City, Kapolei.

Which countries use HST, HST's zone?

HST is used in United States (Hawaii).

Is there a day difference between HST and United Kingdom?

Not normally. The +11h gap only pushes the date over for late-evening times.

What is the time difference between HST and United Kingdom?

United Kingdom is +11h from HST.

What timezone is HST in?

HST operates on its local timezone.

What timezone is United Kingdom in?

United Kingdom operates on its local timezone.

Which countries use HST (Hawaii Standard Time)?

HST is used in United States (Hawaii).

Does HST observe daylight saving time?

No, HST does not observe daylight saving time and remains at UTC-10:00 year-round.

What are some interesting 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.

Which cities are in the GMT timezone?

Major cities in the GMT timezone include London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar.

What is the UTC offset for GMT?

Greenwich Mean Time (GMT) is at UTC+00:00. During daylight saving time, it shifts to BST.

What should I know about the GMT timezone?

GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.