ACST to HKT
-1h 30mACST
ACSTSOURCEHKT
HKTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and HKT on the World Map
The map below highlights the ACST (Australian Central Standard Time) and HKT (Hong Kong Time) timezone regions across the globe.
ACST – Australian Central Standard Time
UTC+09:30Australian Central Standard Time (ACST, UTC+09:30) covers South Australia and the Northern Territory, on a half-hour offset.
- •ACST uses a half-hour offset: UTC+09:30.
- •South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
- •Adelaide and Darwin are 30 minutes apart during daylight saving, level in winter.
- •Adelaide is one of the few major cities on a 30-minute offset.
HKT – Hong Kong Time
UTC+08:00Hong Kong Time (HKT, UTC+08:00) is the time zone for Hong Kong, 8 hours ahead of UTC.
- •Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979.
- •HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
- •The Hong Kong Stock Exchange opens at 09:30 HKT.
- •Hong Kong Time does not change with the seasons, so its gap to other zones is fixed.
Understanding the -1h 30m Gap: ACST vs HKT
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. HKT runs on Hong Kong Time (HKT) at UTC+08:00. That puts ACST 1 hour 30 minutes behind HKT — a difference of -1h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 7:30 AM in HKT. Midnight in ACST is 10:30 PM in HKT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to HKT time conversion table
| ACST (ACST) | HKT (HKT) | Day |
|---|---|---|
| 12:00 AM | 10:30 PM | previous day |
| 6:00 AM | 4:30 AM | same day |
| 7:00 AM | 5:30 AM | same day |
| 8:00 AM | 6:30 AM | same day |
| 9:00 AM | 7:30 AM | same day |
| 12:00 PM | 10:30 AM | same day |
| 3:00 PM | 1:30 PM | same day |
| 5:00 PM | 3:30 PM | same day |
| 6:00 PM | 4:30 PM | same day |
| 9:00 PM | 7:30 PM | same day |
Why people convert ACST to HKT time
- Scheduling a call from ACST to HKT: a 10:00 AM start in ACST lands at 8:30 AM in HKT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both ACST and HKT are inside the 9-to-5 working day between 10:30 AM and 5:00 PM ACST time (9:00 AM–3:30 PM HKT). That is roughly 6 hours 30 minutes of usable overlap.
- Booking travel or deliveries: tracking HKT local time against ACST keeps pickup windows and arrival estimates honest across the -1h 30m offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM ACST" is unambiguous; "3 PM" across a -1h 30m gap is not.
- Block 10:30 AM–5:00 PM ACST as the recurring meeting window if you work primarily from ACST and need HKT colleagues present.
About ACST (Australian Central Standard Time)
Australian Central Standard Time (ACST) is the half-hour offset of UTC+09:30 used across South Australia and the Northern Territory, taking in Adelaide and Darwin. South Australia moves to Australian Central Daylight Time (ACDT, UTC+10:30) from the first Sunday in October to the first Sunday in April, but the Northern Territory does not observe daylight saving — so Adelaide and Darwin sit 30 minutes apart in summer and level with each other in winter. The half-hour offset means Adelaide is 30 minutes behind Sydney in winter and level with it during daylight saving, which regularly catches out travellers and meeting planners.
About HKT (Hong Kong Time)
Hong Kong Time (HKT) is fixed at UTC+08:00 all year and does not observe daylight saving time. Hong Kong last used summer time in 1979 and has kept a single offset since. HKT shares the UTC+08:00 offset with China Standard Time, Singapore Time, Malaysian Time, Philippine Time and Australian Western Standard Time, but is listed separately because Hong Kong maintains its own timekeeping authority. As a major financial centre, Hong Kong's trading hours set the rhythm for markets across Asia, opening at 09:30 HKT which is 01:30 in London and 20:30 the previous evening in New York.
Best time to call between ACST and HKT
Both ACST and HKT sit inside the 9 AM – 5 PM working day between 10:30 AM–5:00 PM ACST, which is 9:00 AM–3:30 PM HKT. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
ACST and HKT share 6 hours of working-hours overlap (10:30 AM–5:00 PM ACST), so scheduling a live meeting is straightforward.
ACST is 1 hour 30 minutes behind HKT (ACST UTC+09:30 → HKT UTC+08:00). The shared working window is 10:30 AM–5:00 PM ACST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
ACST
❄ Currently in Standard Time
Standard: UTC+09:30 · DST: UTC+10:30
Clocks spring forward on Sat, Oct 3, 2026
HKT
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 ACST and HKT?
ACST (ACST, UTC+09:30) is 1 hour 30 minutes behind HKT (HKT, UTC+08:00). The gap is currently -1h 30m.
How do I convert ACST time to HKT time?
Add -1h 30m to ACST local time. For example, 9:00 AM in ACST is 7:30 AM in HKT.
What time is it in HKT right now?
HKT uses HKT at UTC+08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -1h 30m offset from ACST.
What is the best time to call HKT from ACST?
Call between 10:30 AM and 5:00 PM ACST — that maps to 9:00 AM–3:30 PM HKT and keeps both parties inside the working day.
Which is behind, ACST or HKT?
ACST is 1 hour 30 minutes behind HKT. When it is 12:00 PM in ACST it is 10:30 AM in HKT.
Does daylight saving time affect the ACST–HKT difference?
Neither zone observes daylight saving time, so the -1h 30m offset between ACST and HKT is fixed all year.
Which other cities share ACST's time zone?
ACST also covers Adelaide, Darwin, Alice Springs, Mount Gambier.
Which countries use ACST, ACST's zone?
ACST is used in Australia (South Australia, Northern Territory).
Is there a day difference between ACST and HKT?
Not normally. The -1h 30m gap only pushes the date over the previous day.
What is the time difference between ACST and HKT?
HKT is -1h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is HKT in?
HKT operates on its local timezone.
Which countries use ACST (Australian Central Standard Time)?
ACST is used in Australia (South Australia, Northern Territory).
Does ACST observe daylight saving time?
Yes, ACST switches to ACDT during summer months.
What are some interesting facts about ACST?
ACST uses a half-hour offset: UTC+09:30. South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
Which cities are in the HKT timezone?
Major cities in the HKT timezone include Hong Kong, Kowloon, Tsuen Wan, Sha Tin.
What is the UTC offset for HKT?
Hong Kong Time (HKT) is at UTC+08:00.
What should I know about the HKT timezone?
Hong Kong does not observe daylight saving time and has kept UTC+08:00 since 1979. HKT shares its offset with China Standard Time, Singapore Time and Philippine Time.
When is it midnight in ACST, what time is it in HKT?
When it is 12:00 AM (midnight) in ACST (ACST), it is -1h 30m later in HKT (HKT).
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See every conversion from ACST →·See every conversion from HKT →