ACST to SGT
-1h 30mACST
ACSTSOURCESGT
SGTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and SGT on the World Map
The map below highlights the ACST (Australian Central Standard Time) and SGT (Singapore Standard 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.
SGT – Singapore Standard Time
UTC+08:00Singapore Standard Time (SGT) is the time zone for Singapore, 8 hours ahead of UTC.
- •Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00).
- •Singapore does not observe daylight saving time.
- •The Singapore Exchange (SGX) operates on SGT.
Everything You Need to Know About ACST and SGT Time
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. SGT runs on Singapore Standard Time (SGT) at UTC+08:00. That puts ACST 1 hour 30 minutes behind SGT — 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 SGT. Midnight in ACST is 10:30 PM in SGT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to SGT time conversion table
| ACST (ACST) | SGT (SGT) | 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 SGT time
- Scheduling a call from ACST to SGT: a 10:00 AM start in ACST lands at 8:30 AM in SGT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both ACST and SGT are inside the 9-to-5 working day between 10:30 AM and 5:00 PM ACST time (9:00 AM–3:30 PM SGT). That is roughly 6 hours 30 minutes of usable overlap.
- Watching a live event or market open: ACST viewers need 7:30 AM in SGT to catch a 9:00 AM start there, and 1:30 AM if the event is anchored to ACST.
- 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 SGT 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 SGT (Singapore Standard Time)
Singapore Standard Time (SGT) is used in Singapore year-round. Singapore does not observe daylight saving time. Despite being geographically close to the UTC+07:00 zone, Singapore uses UTC+08:00 to align with major trading partners like China, Hong Kong, and Malaysia. Singapore is a major global financial hub.
Best time to call between ACST and SGT
Both ACST and SGT 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 SGT. 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 SGT 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 SGT (ACST UTC+09:30 → SGT 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
SGT
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 SGT?
ACST (ACST, UTC+09:30) is 1 hour 30 minutes behind SGT (SGT, UTC+08:00). The gap is currently -1h 30m.
How do I convert ACST time to SGT time?
Add -1h 30m to ACST local time. For example, 9:00 AM in ACST is 7:30 AM in SGT.
What time is it in SGT right now?
SGT uses SGT 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 SGT from ACST?
Call between 10:30 AM and 5:00 PM ACST — that maps to 9:00 AM–3:30 PM SGT and keeps both parties inside the working day.
Which is behind, ACST or SGT?
ACST is 1 hour 30 minutes behind SGT. When it is 12:00 PM in ACST it is 10:30 AM in SGT.
Does daylight saving time affect the ACST–SGT difference?
Neither zone observes daylight saving time, so the -1h 30m offset between ACST and SGT 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 SGT?
Not normally. The -1h 30m gap only pushes the date over the previous day.
What is the time difference between ACST and SGT?
SGT is -1h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is SGT in?
SGT 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 SGT timezone?
Major cities in the SGT timezone include Singapore.
What is the UTC offset for SGT?
Singapore Standard Time (SGT) is at UTC+08:00.
What should I know about the SGT timezone?
Singapore uses UTC+08:00 despite being at about 104°E longitude (closer to UTC+07:00). Singapore does not observe daylight saving time.
When is it midnight in ACST, what time is it in SGT?
When it is 12:00 AM (midnight) in ACST (ACST), it is -1h 30m later in SGT (SGT).
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See every conversion from ACST →·See every conversion from SGT →