HST to AWST Converter
Convert time between Hawaii Standard Time (HST) and Australian Western Standard Time (AWST)
Hawaii Standard Time (HST)
Australian Western Standard Time (AWST)
Time Difference
Australian Western Standard Time (AWST) is 0 hours ahead of Hawaii Standard Time (HST)
Select Date
Select Time
Quick Reference
| HST | AWST |
|---|---|
| 16:00 | 10:00 |
| 18:00 | 12:00 |
| 20:00 | 14:00 |
| 22:00 | 16:00 |
| 00:00 | 18:00 |
| 02:00 | 20:00 |
| 04:00 | 22:00 |
| 06:00 | 00:00 |
| 08:00 | 02:00 |
| 10:00 | 04:00 |
| 12:00 | 06:00 |
| 14:00 | 08:00 |
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
About HST to AWST Time Conversion
Converting time between Hawaii Standard Time (HST) and Australian Western Standard Time (AWST) spans a significant 18-hour gap across the Pacific. HST is UTC-10, while AWST is UTC+8, making Perth 18 hours ahead of Honolulu. This wide difference means that when it is noon in Hawaii, it is already 6:00 AM the following day in Western Australia.
This time zone converter uses the IANA timezone database for accurate calculations. Neither HST nor AWST observes daylight saving time, so the 18-hour difference remains constant throughout the year. Whether you are coordinating remote teams, planning international travel, or scheduling family calls between Hawaii and Perth, our converter provides reliable results.
Common Use Cases for HST to AWST Conversion
Business & Work
- Scheduling video calls between Hawaii-based teams and Perth offices
- Coordinating project handoffs across the Hawaii-Australia time gap
- Planning webinars and virtual events for both Hawaii and Western Australia audiences
Personal & Travel
- Staying in touch with family and friends between Hawaii and Perth
- Planning travel connections and flight layovers across the Pacific
- Scheduling online gaming sessions or virtual events with participants in both regions
Time Zone Information
Hawaii Standard Time (HST)
- UTC Offset: UTC-10
- IANA Timezone: Pacific/Honolulu
- Daylight Saving: Hawaii does not observe daylight saving time
- Major Cities: Honolulu, Hilo, Kailua, Pearl City, Kaneohe
- Coverage: The Hawaiian Islands, including all of the US state of Hawaii
Australian Western Standard Time (AWST)
- UTC Offset: UTC+8
- IANA Timezone: Australia/Perth
- Daylight Saving: Western Australia does not observe daylight saving time
- Major Cities: Perth, Fremantle, Mandurah, Bunbury, Geraldton
- Coverage: Western Australia, the largest Australian state by area
Quick Reference: HST to AWST
Remember: AWST is always 18 hours ahead of HST, year-round
Frequently Asked Questions
What is the time difference between HST and AWST?
Hawaii Standard Time (HST) is UTC-10, while Australian Western Standard Time (AWST) is UTC+8. AWST is 18 hours ahead of HST. When it's 12:00 PM in Honolulu, it's 6:00 AM the next day in Perth.
Do HST or AWST observe daylight saving time?
Neither Hawaii nor Western Australia observes daylight saving time. Hawaii abolished DST in 1967, and Western Australia voted against it following a trial period. This means the 18-hour difference between HST and AWST remains constant throughout the entire year.
Does the HST to AWST time difference ever change?
No. Because neither HST nor AWST observes daylight saving time, the gap is always exactly 18 hours. You never need to adjust for seasonal clock changes, making year-round scheduling between Hawaii and Perth straightforward.
What are the best times to schedule calls between Hawaii and Perth?
The most practical window is early morning in Hawaii (6:00–9:00 AM HST), which corresponds to midnight to 3:00 AM AWST — difficult for Perth. A better approach is late afternoon in Perth (4:00–6:00 PM AWST), which is 10:00 PM–midnight the previous day in Hawaii. Overlap is very limited, so flexibility on one side is usually required.
Which regions use Australian Western Standard Time (AWST)?
AWST is used exclusively by Western Australia, Australia's largest state. Major cities include Perth, Fremantle, Mandurah, Bunbury, and Geraldton. Western Australia is geographically isolated from the eastern states, which use AEST/AEDT (UTC+10/+11).
Which regions use Hawaii Standard Time (HST)?
HST is used by the US state of Hawaii and the unincorporated territory of Midway Atoll. Honolulu is the largest city. Hawaii is the only US state that does not observe daylight saving time and does not share a timezone with any US mainland state.
Pro Tips
- • AWST is always 18 hours ahead of HST — add 18 hours (and typically one calendar day) to convert HST to AWST.
- • Neither timezone uses DST, so the 18-hour gap never changes — no need to recalculate for summer or winter.
- • When scheduling across this gap, pick a time that is morning in Perth (8–10 AM AWST), which lands around 2–4 PM the previous day in Hawaii.
- • Perth and Honolulu are often on different calendar dates — always confirm the date when sharing a meeting time.
- • Hawaii sits in the central Pacific while Western Australia borders the Indian Ocean — the two regions are separated by over 10,000 km.
- • For recurring meetings, anchor on the Perth side and let Hawaii adjust, as AWST aligns with Asian business hours more naturally.