ACST to Osaka
-0h 30mACST
ACSTSOURCEOsaka
JSTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and JST on the World Map
The map below highlights the ACST (Australian Central Standard Time) and JST (Japan 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.
JST – Japan Standard Time
UTC+09:00Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.
- •Japan does not observe daylight saving time.
- •Tokyo is the most populous metropolitan area in the world.
- •The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
- •JST is 14 hours ahead of EST and 9 hours ahead of GMT.
About Osaka
WikipediaOsaka operates on Japan Standard Time (JST), UTC+9. As Japan's second economic center and a manufacturing hub, Osaka shares business hours with Tokyo.
Osaka Castle was originally built in 1583 and has been rebuilt several times.
Understanding the -0h 30m Gap: ACST vs Osaka
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. Osaka runs on Japan Standard Time (JST) at UTC+09:00. That puts ACST 30 minutes behind Osaka — a difference of -0h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 8:30 AM in Osaka. Midnight in ACST is 11:30 PM in Osaka. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to Osaka time conversion table
| ACST (ACST) | Osaka (JST) | 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 ACST to Osaka time
- Scheduling a call from ACST to Osaka: a 10:00 AM start in ACST lands at 9:30 AM in Osaka, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both ACST and Osaka are inside the 9-to-5 working day between 9:30 AM and 5:00 PM ACST time (9:00 AM–4:30 PM JST). That is roughly 7 hours 30 minutes of usable overlap.
- Booking travel or deliveries: tracking Osaka local time against ACST keeps pickup windows and arrival estimates honest across the -0h 30m offset.
- Always state the zone abbreviation, not just the hour. "3:00 PM ACST" is unambiguous; "3 PM" across a -0h 30m gap is not.
- Block 9:30 AM–5:00 PM ACST as the recurring meeting window if you work primarily from ACST and need Osaka 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 JST (Japan Standard Time)
Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.
Best time to call between ACST and Osaka
Both ACST and Osaka sit inside the 9 AM – 5 PM working day between 9:30 AM–5:00 PM ACST, which is 9:00 AM–4:30 PM JST. That gives roughly 7 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
ACST and Osaka share 7 hours of working-hours overlap (9:30 AM–5:00 PM ACST), so scheduling a live meeting is straightforward.
ACST is 30 minutes behind Osaka (ACST UTC+09:30 → JST UTC+09:00). The shared working window is 9:30 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
Osaka
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 Osaka?
ACST (ACST, UTC+09:30) is 30 minutes behind Osaka (JST, UTC+09:00). The gap is currently -0h 30m.
How do I convert ACST time to Osaka time?
Add -0h 30m to ACST local time. For example, 9:00 AM in ACST is 8:30 AM in Osaka.
What time is it in Osaka right now?
Osaka uses JST at UTC+09:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -0h 30m offset from ACST.
What is the best time to call Osaka from ACST?
Call between 9:30 AM and 5:00 PM ACST — that maps to 9:00 AM–4:30 PM JST and keeps both parties inside the working day.
Which is behind, ACST or Osaka?
ACST is 30 minutes behind Osaka. When it is 12:00 PM in ACST it is 11:30 AM in Osaka.
Do ACST and Osaka use different time zones?
ACST uses ACST at UTC+09:30, while Osaka (Japan) uses JST at UTC+09:00. The IANA identifiers are Australia/Adelaide and Asia/Tokyo.
Does daylight saving time affect the ACST–Osaka difference?
Neither zone observes daylight saving time, so the -0h 30m offset between ACST and Osaka 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 Osaka?
Not normally. The -0h 30m gap only pushes the date over the previous day.
What is the time difference between ACST and Osaka?
Osaka is -0h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is Osaka in?
Osaka operates on Japan Standard Time (JST), UTC+9. As Japan's second economic center and a manufacturing hub, Osaka shares business hours with Tokyo.
What are the business hours in Osaka?
Standard business hours in Osaka are 9:00 AM - 6:00 PM JST.
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 JST timezone?
Major cities in the JST timezone include Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Kobe, Fukuoka.
What is the UTC offset for JST?
Japan Standard Time (JST) is at UTC+09:00.
What should I know about the JST timezone?
Japan does not observe daylight saving time. Tokyo is the most populous metropolitan area in the world.
When is it midnight in ACST, what time is it in Osaka?
When it is 12:00 AM (midnight) in ACST (ACST), it is -0h 30m later in Osaka (JST).
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