HST to BST Converter
Convert time between Hawaii Standard Time (HST) and British Summer Time (BST)
Hawaii Standard Time (HST)
British Summer Time (BST)
Time Difference
British Summer Time (BST) is 0 hours ahead of Hawaii Standard Time (HST)
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Select Time
Quick Reference
| HST | BST |
|---|---|
| 16:00 | 02:00 |
| 18:00 | 04:00 |
| 20:00 | 06:00 |
| 22:00 | 08:00 |
| 00:00 | 10:00 |
| 02:00 | 12:00 |
| 04:00 | 14:00 |
| 06:00 | 16:00 |
| 08:00 | 18:00 |
| 10:00 | 20:00 |
| 12:00 | 22:00 |
| 14:00 | 00:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
Related Time Zone Conversions
About HST to BST Time Conversion
Converting time between Hawaii Standard Time (HST) and British Summer Time (BST) is important for coordinating between Hawaii and the United Kingdom during daylight saving time. HST is UTC-10 year-round, while BST is UTC+1 (observed late March to late October). BST is 11 hours ahead of HST during the summer season.
This conversion is vital for international businesses coordinating between Hawaii and the UK. Whether you're scheduling meetings between Honolulu and London, managing distributed teams across the Atlantic and Pacific, or planning travel between Hawaiian and UK destinations, our accurate IANA-based converter ensures precise timezone calculations. The substantial 11-hour difference requires careful attention to scheduling to find overlapping hours for business communication.
Common Use Cases for HST to BST Conversion
Business & Work
- Scheduling calls between Hawaii and UK offices during daylight saving time
- Coordinating between Hawaii and UK headquarters
- Managing business operations across Hawaii and UK regions
- Planning conference calls between Hawaii and UK teams
Personal & Travel
- Scheduling video calls with family and friends in the UK
- Planning travel between Hawaii and UK destinations
- Coordinating vacation time across regions during summer months
- Arranging online meetings with UK-based colleagues
Time Zone Information
Hawaii Standard Time (HST)
- UTC Offset: UTC-10
- IANA Timezone: Pacific/Honolulu
- Daylight Saving: No daylight saving time observed
- Major Cities: Honolulu, Hilo, Maui, Kauai, Big Island
- Coverage: State of Hawaii
British Summer Time (BST)
- UTC Offset: UTC+1 (UTC+0 during GMT)
- IANA Timezone: Europe/London
- Daylight Saving: Late March to Late October
- Major Cities: London, Manchester, Edinburgh, Cardiff, Birmingham
- Coverage: United Kingdom
Quick Reference: HST to BST
Remember: BST is 11 hours ahead of HST during daylight saving time (late March to late October). When BST ends and GMT begins (UTC+0), the difference decreases to 10 hours. Hawaii does not observe daylight saving time, so HST remains constant year-round.
Frequently Asked Questions
What is the time difference between HST and BST?
Hawaii Standard Time (HST) is UTC-10, while British Summer Time (BST) is UTC+1. BST is 11 hours ahead of HST. This means when it's 8:00 AM in HST, it's 7:00 PM the same day in BST.
Does Hawaii observe daylight saving time?
No, Hawaii does not observe daylight saving time. Hawaii Standard Time (HST) remains UTC-10 year-round. However, the UK observes daylight saving time, with BST (UTC+1) active from late March to late October, and GMT (UTC+0) the rest of the year. This means the time difference varies between 10 hours (when GMT is active) and 11 hours (when BST is active).
How does HST to BST differ from HST to GMT?
BST (British Summer Time) is 1 hour ahead of GMT (Greenwich Mean Time). When BST is active (late March to late October), the difference between HST and BST is 11 hours. When GMT is active (late October to late March), the difference between HST and GMT is 10 hours. BST is used during daylight saving time in the UK.
What major cities are in HST and BST timezones?
HST covers Hawaii cities including Honolulu, Hilo, Maui, Kauai, and the Big Island. BST covers major UK cities and regions including London, Manchester, Edinburgh, Cardiff, and Birmingham. These regions represent Hawaii and the United Kingdom during daylight saving time (late March to late October).
How do I convert HST to BST manually?
To convert from HST to BST, add 11 hours to the HST time. For example, if it's 9:00 AM HST, it would be 8:00 PM BST the same day. Remember this conversion applies during BST (late March to late October). When GMT is active (late October to late March), add only 10 hours instead.
What should I know about scheduling across HST and BST?
Hawaii is 11 hours behind the UK during BST, making coordination very challenging with minimal overlap. Morning BST times (9-11 AM) correspond to late evening/night HST times (10 PM-12 AM), and afternoon BST (3-5 PM) corresponds to very early morning HST (4-6 AM). For business coordination, early morning BST calls (7-9 AM) work with HST afternoon (2-4 PM) or evening hours (6-8 PM), offering limited but possible overlap.
Pro Tips
- • BST is always 11 hours ahead of HST during daylight saving time (late March to late October). Outside this period, GMT is 10 hours ahead.
- • Hawaii does not observe daylight saving time, so HST is consistent year-round while BST/GMT changes twice annually (dates differ from US).
- • The 11-hour difference means business hours have minimal overlap - early BST morning (7-9 AM) aligns with HST evening (2-4 PM).
- • Early morning BST calls (7-8 AM) work well with HST afternoon/evening schedules (2-3 PM), providing a narrow window for synchronous meetings.
- • Use 24-hour time format when communicating across HST-BST to eliminate AM/PM confusion with this substantial time difference.
- • International business between Hawaii and the UK often requires asynchronous communication or creative scheduling to accommodate the 11-hour offset.