ACST to PST
-17h 30mACST
ACSTSOURCEPST
PSTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and PST on the World Map
The map below highlights the ACST (Australian Central Standard Time) and PST (Pacific 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.
PST – Pacific Standard Time
UTC-08:00Pacific Standard Time (PST) is the time zone for the US and Canadian Pacific coast, 8 hours behind UTC.
- •Silicon Valley and the world's biggest tech companies operate on Pacific Time.
- •The Hollywood film industry runs on PST/PDT.
- •PST is 3 hours behind EST, creating a significant business hours gap.
- •Vancouver, Canada's third-largest city, uses PST.
Understanding the -17h 30m Gap: ACST vs PST
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. PST runs on Pacific Standard Time (PST) at UTC-08:00. That puts ACST 17 hours 30 minutes behind PST — a difference of -17h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 3:30 PM in PST on the previous day. Midnight in ACST is 6:30 AM in PST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to PST time conversion table
| ACST (ACST) | PST (PST) | Day |
|---|---|---|
| 12:00 AM | 6:30 AM | previous day |
| 6:00 AM | 12:30 PM | previous day |
| 7:00 AM | 1:30 PM | previous day |
| 8:00 AM | 2:30 PM | previous day |
| 9:00 AM | 3:30 PM | previous day |
| 12:00 PM | 6:30 PM | previous day |
| 3:00 PM | 9:30 PM | previous day |
| 5:00 PM | 11:30 PM | previous day |
| 6:00 PM | 12:30 AM | same day |
| 9:00 PM | 3:30 AM | same day |
Why people convert ACST to PST time
- Scheduling a call from ACST to PST: a 10:00 AM start in ACST lands at 4:30 PM in PST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -17h 30m gap: ACST and PST 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 PST is 3:30 PM in ACST.
- Coordinating a ACST-based team with PST 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 ACST" is unambiguous; "3 PM" across a -17h 30m gap is not.
- With a -17h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week ACST takes the early slot, the next week PST does.
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 PST (Pacific Standard Time)
Pacific Standard Time (PST) covers the west coast of North America, including tech hubs like San Francisco and Seattle, and entertainment capital Los Angeles. The Pacific Time Zone is home to Silicon Valley and the world's largest technology companies. During summer, clocks advance to Pacific Daylight Time (PDT, UTC-07:00). PST is also observed in Baja California, Mexico.
Best time to call between ACST and PST
With a -17h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. PST opens at 9:00 AM PST, which is 3:30 PM in ACST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
ACST and PST have no shared working hours because of the -17h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.
ACST is 17 hours 30 minutes behind PST (ACST UTC+09:30 → PST UTC-08:00). 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
ACST
❄ Currently in Standard Time
Standard: UTC+09:30 · DST: UTC+10:30
Clocks spring forward on Sat, Oct 3, 2026
PST
☀ Currently in DST
Standard: UTC-08:00 · DST: UTC-07:00
Clocks fall back on Sun, Nov 1, 2026
⚠ These locations are currently in different DST states, so the time difference may change when clocks adjust.
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 PST?
ACST (ACST, UTC+09:30) is 17 hours 30 minutes behind PST (PST, UTC-08:00). The gap is currently -17h 30m.
How do I convert ACST time to PST time?
Add -17h 30m to ACST local time. For example, 9:00 AM in ACST is 3:30 PM in PST (previous day).
What time is it in PST right now?
PST uses PST at UTC-08:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -17h 30m offset from ACST.
What is the best time to call PST from ACST?
There is no shared working-hours window because of the -17h 30m gap. The closest option is 1:00 PM in ACST, which is 7:30 PM in PST.
Which is behind, ACST or PST?
ACST is 17 hours 30 minutes behind PST. When it is 12:00 PM in ACST it is 6:30 PM in PST.
Does daylight saving time affect the ACST–PST difference?
Neither zone observes daylight saving time, so the -17h 30m offset between ACST and PST 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 PST?
Sometimes. The -17h 30m gap is large enough that 8:00 PM or later in ACST already falls on the in PST.
What is the time difference between ACST and PST?
PST is -17h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is PST in?
PST 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 PST timezone?
Major cities in the PST timezone include Los Angeles, San Francisco, Seattle, Vancouver, San Diego, Portland, Las Vegas, Sacramento.
What is the UTC offset for PST?
Pacific Standard Time (PST) is at UTC-08:00. During daylight saving time, it shifts to PDT.
What should I know about the PST timezone?
Silicon Valley and the world's biggest tech companies operate on Pacific Time. The Hollywood film industry runs on PST/PDT.
When is it midnight in ACST, what time is it in PST?
When it is 12:00 AM (midnight) in ACST (ACST), it is -17h 30m later in PST (PST).
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See every conversion from ACST →·See every conversion from PST →