What is the time difference between HST and GMT?

Greenwich Mean Time (GMT) is 11 hours ahead of Hawaii Standard Time (HST). HST uses a UTC offset of UTC-10, while GMT uses UTC+1. For example, when it's 9:00 AM in HST, it's 8:00 PM in GMT. Note that this difference may shift by one hour during daylight saving time transitions if GMT observes DST. Use the conversion table above to see the exact time for each hour of the day.

How do I convert HST to GMT?

To convert HST to GMT, add 11 hours to the HST time. For example, 9:00 AM HST is 8:00 PM GMT, and 5:00 PM HST is 4:00 AM GMT. Keep in mind that during daylight saving time transitions, the offset between these timezones may temporarily change by one hour. You can also use the interactive converter above for quick, accurate results.

What time is it in GMT when it's noon in HST?

When it's 12:00 PM (noon) in HST, it's 11:00 PM in GMT. This is because GMT is 11 hours ahead of HST. Similarly, when it's 6:00 PM in HST, it's 5:00 AM in GMT. During daylight saving time transitions, these times may shift by one hour, so always verify the current offset. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours ahead is GMT from HST?

GMT is 11 hours ahead of HST. This means when it's 9:00 AM in HST, it's 8:00 PM in GMT, and when it's midnight in HST, it's 11:00 AM in GMT. The exact difference can vary by one hour during daylight saving time transitions. The conversion table above provides a complete hour-by-hour mapping.

Is GMT ahead or behind HST?

GMT is ahead of HST by 11 hours. Clocks in GMT show a later time than HST, meaning the day starts earlier in GMT relative to HST. For example, when it's morning in HST, it's already afternoon or evening in GMT. This gap may change by one hour during DST transitions.

Does HST observe daylight saving time?

No, Hawaii Standard Time does not observe daylight saving time. The UTC offset of UTC-10 remains the same year-round, making time conversions from HST more predictable. Countries and regions in this timezone keep their clocks unchanged regardless of the season.

Does GMT observe daylight saving time?

Yes, Greenwich Mean Time observes daylight saving time. During DST, the abbreviation changes to BST and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard GMT time. This means the UTC offset for GMT shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your HST to GMT conversions.

What is the best time to call from HST to GMT?

The best time for a call between HST and GMT is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in GMT during their work day, call between 10:00 PM and 6:00 AM your HST time. Avoid calling too early or late, as the 11 hours difference means your evening could be their late night. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

When does daylight saving time change in GMT?

Daylight saving time transitions vary by year and region. Greenwich Mean Time observes DST, which typically shifts clocks forward by one hour in spring ("spring forward") and back in fall ("fall back"). During these transition periods, the time difference between HST and GMT may temporarily change by one hour, which can cause confusion for scheduled meetings or calls. It's important to double-check your conversions around transition dates, especially if the two timezones switch on different dates. Check our DST change calendar for exact transition dates in the current year.

Do HST and GMT ever have the same time?

No, HST and GMT never show the same time because their base UTC offsets are different. However, because GMT observes daylight saving time and HST does not, the time difference between them changes by one hour during DST transitions. This means the gap narrows or widens depending on the season, but the two clocks never align. Always verify the current offset around DST transition dates to avoid scheduling errors.

HST to GMT Converter

Convert Hawaii Standard Time to Greenwich Mean Time. See the hour-by-hour conversion table below.

Timezone Details

Hawaii Standard Time

12:36 PM

Friday, April 3, 2026

HST (UTC-10:00)

Greenwich Mean Time

11:36 PM

Friday, April 3, 2026

BST (UTC+01:00)

Difference: +11 hours

HST DST: No

BST DST: Yes (BST)

24-Hour Overview

HST — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

BST — 24-hour overview

11a11a

12p

2p2p

5p5p

8p8p

10p

11p11p

12a

2a2a

5a5a

8a8a

10a

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

GMT to HST EST to GMT GMT to EST PST to GMT GMT to PST GMT to IST IST to GMT GMT to CET CET to GMT

Cities in These Timezones

HST Cities

Honolulu

GMT Cities

London Manchester Edinburgh

More Tools

Compare HST & GMT Plan a Meeting (HST & GMT)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Hawaii Standard Time on Wikipedia Greenwich Mean Time on Wikipedia IANA Time Zone Database