HST to AEDT Converter & Meeting Planner
Quick answer: 9:00 AM HST = 6:00 AM AEDT (fixed -10:00 standard offset — not DST-adjusted). Use the interactive converter below for DST-aware local-time scheduling.
Planning a call or meeting between Hawaii-Aleutian Standard Time (HST) and Australian Eastern Daylight Time (AEDT)? You need to account for the standard time difference. Australian Eastern Daylight Time is normally 21 hours ahead of Hawaii-Aleutian Standard Time. Whether you are coordinating between teams in Honolulu and Hilo and Sydney and Melbourne, our live tool has you covered. Use our interactive overlap studio below to find the perfect waking hours for both regions, taking into account any seasonal Daylight Saving Time (DST) changes.
24-Hour Conversion Table
Quick reference: 12:00 AM HST = 9:00 PM AEDT. The full 24-hour HST to AEDT table below uses fixed standard offsets for exact abbreviation searches.
Example: 3:00 PM HST = 12:00 PM AEDT (+1 day).
| HST Time | AEDT Time |
|---|---|
| 12:00 AM (00:00) | 9:00 PM (21:00) |
| 1:00 AM (01:00) | 10:00 PM (22:00) |
| 2:00 AM (02:00) | 11:00 PM (23:00) |
| 3:00 AM (03:00) | 12:00 AM (00:00)+1 day |
| 4:00 AM (04:00) | 1:00 AM (01:00)+1 day |
| 5:00 AM (05:00) | 2:00 AM (02:00)+1 day |
| 6:00 AM (06:00) | 3:00 AM (03:00)+1 day |
| 7:00 AM (07:00) | 4:00 AM (04:00)+1 day |
| 8:00 AM (08:00) | 5:00 AM (05:00)+1 day |
| 9:00 AM (09:00) | 6:00 AM (06:00)+1 day |
| 10:00 AM (10:00) | 7:00 AM (07:00)+1 day |
| 11:00 AM (11:00) | 8:00 AM (08:00)+1 day |
| 12:00 PM (12:00) | 9:00 AM (09:00)+1 day |
| 1:00 PM (13:00) | 10:00 AM (10:00)+1 day |
| 2:00 PM (14:00) | 11:00 AM (11:00)+1 day |
| 3:00 PM (15:00) | 12:00 PM (12:00)+1 day |
| 4:00 PM (16:00) | 1:00 PM (13:00)+1 day |
| 5:00 PM (17:00) | 2:00 PM (14:00)+1 day |
| 6:00 PM (18:00) | 3:00 PM (15:00)+1 day |
| 7:00 PM (19:00) | 4:00 PM (16:00)+1 day |
| 8:00 PM (20:00) | 5:00 PM (17:00)+1 day |
| 9:00 PM (21:00) | 6:00 PM (18:00)+1 day |
| 10:00 PM (22:00) | 7:00 PM (19:00)+1 day |
| 11:00 PM (23:00) | 8:00 PM (20:00)+1 day |
Best time to call Sydney from Honolulu
For most work calls, compare the normal business day in Honolulu (HST) with the business day in Sydney (AEDT). HST commonly covers Pacific Ocean, North America, while AEDT is mainly associated with Oceania, Eastern Australia.
⚠️ Note: 2026-07-05 is not a normal workday in one or both regions based on their configured calendar. The overlap below should be treated as a reference, not a guaranteed office-hours window.
✅ The most practical overlap on 2026-07-05 is usually 1:00 PM - 5:00 PM HST, which corresponds to 9:00 AM - 1:00 PM AEDT. This window sits inside the typical HST workday (9:00 AM - 5:00 PM) and the AEDT workday (9:00 AM - 5:00 PM).
- DST Safety: HST or AEDT may shift during Daylight Saving Time. Always confirm the converted time for your specific date.
- Australian Securities Exchange (ASX): 10:00-16:00 local time in Sydney.
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Frequently Asked Questions
What is the time difference between HST and AEDT?
During standard time, Australian Eastern Daylight Time is 21 hours ahead of Hawaii-Aleutian Standard Time.
Does Hawaii observe Daylight Saving Time?
Hawaii does not observe Daylight Saving Time and has not done so since 1947, remaining fixed at UTC-10:00 year-round. At roughly 20° North latitude, Hawaii's daylight hours vary by only about 1.5 hours between the summer and winter solstices — far too little to justify the disruption of a seasonal clock change.
Why is it called Hawaii-Aleutian time?
The name combines two geographically distant US territories that share the same UTC-10:00 standard offset: the Hawaiian Islands in the central Pacific and the westernmost Aleutian Islands of Alaska, which extend past the 180° meridian into the Eastern Hemisphere. Despite sharing a base offset, they behave differently — Hawaii observes no DST, while the Aleutian communities such as Adak do advance to HDT (UTC-9) each summer.
When does AEDT start and end?
AEDT begins on the first Sunday in October at 02:00 local time, when clocks spring forward one hour from AEST (UTC+10) to AEDT (UTC+11). It ends on the first Sunday in April at 03:00 local time, when clocks fall back to AEST. In 2026, AEDT starts on October 4 and ends on April 5 — following the Southern Hemisphere summer calendar, which runs opposite to DST schedules in Europe and North America.
Is Brisbane on AEDT?
No — Queensland, including Brisbane, does not observe Daylight Saving Time and remains on AEST (UTC+10) year-round. During the AEDT period from October through April, Sydney and Melbourne advance to UTC+11 while Brisbane stays at UTC+10, creating a one-hour gap between cities that share nearly the same longitude and are otherwise in the same time zone for the other six months of the year.