Sydney to HST
-20hSydney
AESTSOURCEHST
HSTGreen rows indicate typical business hours (9 AM - 5 PM)
AEST and HST on the World Map
The map below highlights the AEST (Australian Eastern Standard Time) and HST (Hawaii Standard Time) timezone regions across the globe.
AEST – Australian Eastern Standard Time
UTC+10:00Australian Eastern Standard Time (AEST) covers eastern Australia, 10 hours ahead of UTC.
- •Queensland does not observe daylight saving time, staying on AEST year-round.
- •Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
- •The Australian Securities Exchange (ASX) operates on AEST/AEDT.
- •AEST is 15 hours ahead of EST during winter.
HST – Hawaii Standard Time
UTC-10:00Hawaii Standard Time (HST) is the time zone for the Hawaiian Islands, 10 hours behind UTC.
- •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).
About Sydney
WikipediaSydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.
Sydney is one of the first major cities to welcome the New Year.
Sydney to HST Time Difference – Complete Guide
Sydney runs on Australian Eastern Standard Time (AEST) at UTC+10:00. HST runs on Hawaii Standard Time (HST) at UTC-10:00. That puts Sydney 20 hours behind HST — a difference of -20h at the current offsets.
In practice, when it is 9:00 AM in Sydney it is 1:00 PM in HST on the previous day. Midnight in Sydney is 4:00 AM in HST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Sydney to HST time conversion table
| Sydney (AEST) | HST (HST) | Day |
|---|---|---|
| 12:00 AM | 4:00 AM | previous day |
| 6:00 AM | 10:00 AM | previous day |
| 7:00 AM | 11:00 AM | previous day |
| 8:00 AM | 12:00 PM | previous day |
| 9:00 AM | 1:00 PM | previous day |
| 12:00 PM | 4:00 PM | previous day |
| 3:00 PM | 7:00 PM | previous day |
| 5:00 PM | 9:00 PM | previous day |
| 6:00 PM | 10:00 PM | previous day |
| 9:00 PM | 1:00 AM | same day |
Why people convert Sydney to HST time
- Scheduling a call from Sydney to HST: a 10:00 AM start in Sydney lands at 2:00 PM in HST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -20h gap: Sydney and HST 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 HST is 1:00 PM in Sydney.
- Coordinating a Sydney-based team with HST 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 AEST" is unambiguous; "3 PM" across a -20h gap is not.
- With a -20h gap there is no shared 9-to-5 window, so alternate the early start: one week Sydney takes the early slot, the next week HST does.
- Sydney: Clocks spring forward on Sat, Oct 3, 2026. Re-check this page after that date because the offset changes and so does the -20h gap.
About AEST (Australian Eastern Standard Time)
Australian Eastern Standard Time (AEST) is used in the eastern states of Australia including New South Wales, Victoria, Queensland, Tasmania, and the ACT. During summer (October to April), NSW, VIC, TAS, and ACT switch to Australian Eastern Daylight Time (AEDT, UTC+11:00), while Queensland remains on AEST year-round.
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.
Best time to call between Sydney and HST
With a -20h offset there is no overlap inside a normal 9 AM – 5 PM day. HST opens at 9:00 AM HST, which is 1:00 PM in Sydney, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Sydney and HST have no shared working hours because of the -20h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Sydney is 20 hours behind HST (AEST UTC+10:00 → HST UTC-10:00). 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
Sydney
❄ Currently in Standard Time
Standard: UTC+10:00 · DST: UTC+11:00
Clocks spring forward on Sat, Oct 3, 2026
HST
Does not observe DST
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between Sydney and HST?
Sydney (AEST, UTC+10:00) is 20 hours behind HST (HST, UTC-10:00). The gap is currently -20h.
How do I convert Sydney time to HST time?
Add -20h to Sydney local time. For example, 9:00 AM in Sydney is 1:00 PM in HST (previous day).
What time is it in HST right now?
HST uses HST at UTC-10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -20h offset from Sydney.
What is the best time to call HST from Sydney?
There is no shared working-hours window because of the -20h gap. The closest option is 1:00 PM in Sydney, which is 5:00 PM in HST.
Which is behind, Sydney or HST?
Sydney is 20 hours behind HST. When it is 12:00 PM in Sydney it is 4:00 PM in HST.
Do Sydney and HST use different time zones?
Sydney (Australia) uses AEST at UTC+10:00, while HST uses HST at UTC-10:00. The IANA identifiers are Australia/Sydney and Pacific/Honolulu.
Does daylight saving time affect the Sydney–HST difference?
Neither zone observes daylight saving time, so the -20h offset between Sydney and HST is fixed all year.
Which other cities share Sydney's time zone?
AEST also covers Sydney, Melbourne, Brisbane, Canberra, Hobart, Gold Coast.
Which countries use AEST, Sydney's zone?
AEST is used in Australia (NSW, VIC, QLD, TAS, ACT), Papua New Guinea.
Is there a day difference between Sydney and HST?
Sometimes. The -20h gap is large enough that 8:00 PM or later in Sydney already falls on the in HST.
What is the time difference between Sydney and HST?
HST is -20h from Sydney.
What timezone is Sydney in?
Sydney operates on Australian Eastern Standard Time (AEST/AEDT). As Australia's financial capital, Sydney opens global markets at the start of the business day.
What timezone is HST in?
HST operates on its local timezone.
What are the business hours in Sydney?
Standard business hours in Sydney are 9:00 AM - 5:00 PM AEST.
Which countries use AEST (Australian Eastern Standard Time)?
AEST is used in Australia (NSW, VIC, QLD, TAS, ACT), Papua New Guinea.
Does AEST observe daylight saving time?
Yes, AEST switches to AEDT during summer months.
What are some interesting facts about AEST?
Queensland does not observe daylight saving time, staying on AEST year-round. Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
Which cities are in the HST timezone?
Major cities in the HST timezone include Honolulu, Hilo, Kailua, Pearl City, Kapolei.
What is the UTC offset for HST?
Hawaii Standard Time (HST) is at UTC-10:00.
What should I know about the HST timezone?
Hawaii does not observe daylight saving time. HST is 5 hours behind EST in winter and 6 hours behind EDT in summer.
When is it midnight in Sydney, what time is it in HST?
When it is 12:00 AM (midnight) in Sydney (AEST), it is -20h later in HST (HST).
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