Sydney to ACST
-0h 30mSydney
AESTSOURCEACST
ACSTGreen rows indicate typical business hours (9 AM - 5 PM)
AEST and ACST on the World Map
The map below highlights the AEST (Australian Eastern Standard Time) and ACST (Australian Central 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.
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.
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 ACST Time Difference – Complete Guide
Sydney runs on Australian Eastern Standard Time (AEST) at UTC+10:00. ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. That puts Sydney 30 minutes behind ACST — a difference of -0h 30m at the current offsets.
In practice, when it is 9:00 AM in Sydney it is 8:30 AM in ACST. Midnight in Sydney is 11:30 PM in ACST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Sydney to ACST time conversion table
| Sydney (AEST) | ACST (ACST) | Day |
|---|---|---|
| 12:00 AM | 11:30 PM | previous day |
| 6:00 AM | 5:30 AM | same day |
| 7:00 AM | 6:30 AM | same day |
| 8:00 AM | 7:30 AM | same day |
| 9:00 AM | 8:30 AM | same day |
| 12:00 PM | 11:30 AM | same day |
| 3:00 PM | 2:30 PM | same day |
| 5:00 PM | 4:30 PM | same day |
| 6:00 PM | 5:30 PM | same day |
| 9:00 PM | 8:30 PM | same day |
Why people convert Sydney to ACST time
- Scheduling a call from Sydney to ACST: a 10:00 AM start in Sydney lands at 9:30 AM in ACST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Sydney and ACST are inside the 9-to-5 working day between 9:30 AM and 5:00 PM AEST time (9:00 AM–4:30 PM ACST). That is roughly 7 hours 30 minutes of usable overlap.
- Watching a live event or market open: Sydney viewers need 8:30 AM in ACST to catch a 9:00 AM start there, and 12:30 AM if the event is anchored to Sydney.
- Always state the zone abbreviation, not just the hour. "3:00 PM AEST" is unambiguous; "3 PM" across a -0h 30m gap is not.
- Block 9:30 AM–5:00 PM AEST as the recurring meeting window if you work primarily from Sydney and need ACST colleagues present.
- Sydney: Clocks spring forward on Sat, Oct 3, 2026. Re-check this page after that date because the offset changes and so does the -0h 30m 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 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.
Best time to call between Sydney and ACST
Both Sydney and ACST sit inside the 9 AM – 5 PM working day between 9:30 AM–5:00 PM AEST, which is 9:00 AM–4:30 PM ACST. That gives roughly 7 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Sydney and ACST share 7 hours of working-hours overlap (9:30 AM–5:00 PM AEST), so scheduling a live meeting is straightforward.
Sydney is 30 minutes behind ACST (AEST UTC+10:00 → ACST UTC+09:30). The shared working window is 9:30 AM–5:00 PM AEST. 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
ACST
❄ Currently in Standard Time
Standard: UTC+09:30 · DST: UTC+10:30
Clocks spring forward on Sat, Oct 3, 2026
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 ACST?
Sydney (AEST, UTC+10:00) is 30 minutes behind ACST (ACST, UTC+09:30). The gap is currently -0h 30m.
How do I convert Sydney time to ACST time?
Add -0h 30m to Sydney local time. For example, 9:00 AM in Sydney is 8:30 AM in ACST.
What time is it in ACST right now?
ACST uses ACST at UTC+09:30. Use the live converter at the top of this page — it updates in real time and already accounts for the -0h 30m offset from Sydney.
What is the best time to call ACST from Sydney?
Call between 9:30 AM and 5:00 PM AEST — that maps to 9:00 AM–4:30 PM ACST and keeps both parties inside the working day.
Which is behind, Sydney or ACST?
Sydney is 30 minutes behind ACST. When it is 12:00 PM in Sydney it is 11:30 AM in ACST.
Do Sydney and ACST use different time zones?
Sydney (Australia) uses AEST at UTC+10:00, while ACST uses ACST at UTC+09:30. The IANA identifiers are Australia/Sydney and Australia/Adelaide.
Does daylight saving time affect the Sydney–ACST difference?
Neither zone observes daylight saving time, so the -0h 30m offset between Sydney and ACST 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 ACST?
Not normally. The -0h 30m gap only pushes the date over the previous day.
What is the time difference between Sydney and ACST?
ACST is -0h 30m 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 ACST in?
ACST 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 ACST timezone?
Major cities in the ACST timezone include Adelaide, Darwin, Alice Springs, Mount Gambier.
What is the UTC offset for ACST?
Australian Central Standard Time (ACST) is at UTC+09:30. During daylight saving time, it shifts to ACDT.
What should I know about the ACST timezone?
ACST uses a half-hour offset: UTC+09:30. South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
When is it midnight in Sydney, what time is it in ACST?
When it is 12:00 AM (midnight) in Sydney (AEST), it is -0h 30m later in ACST (ACST).
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