ACST to AKST
-18h 30mACST
ACSTSOURCEAKST
AKSTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and AKST on the World Map
The map below highlights the ACST (Australian Central Standard Time) and AKST (Alaska 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.
AKST – Alaska Standard Time
UTC-09:00Alaska Standard Time (AKST) is the time zone for the state of Alaska, 9 hours behind UTC.
- •Alaska is the largest US state by area but has only about 730,000 residents.
- •Anchorage is the most populous city in AKST with about 290,000 people.
- •The Aleutian Islands use HAST instead of AKST.
Understanding the -18h 30m Gap: ACST vs AKST
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. AKST runs on Alaska Standard Time (AKST) at UTC-09:00. That puts ACST 18 hours 30 minutes behind AKST — a difference of -18h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 2:30 PM in AKST on the previous day. Midnight in ACST is 5:30 AM in AKST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to AKST time conversion table
| ACST (ACST) | AKST (AKST) | Day |
|---|---|---|
| 12:00 AM | 5:30 AM | previous day |
| 6:00 AM | 11:30 AM | previous day |
| 7:00 AM | 12:30 PM | previous day |
| 8:00 AM | 1:30 PM | previous day |
| 9:00 AM | 2:30 PM | previous day |
| 12:00 PM | 5:30 PM | previous day |
| 3:00 PM | 8:30 PM | previous day |
| 5:00 PM | 10:30 PM | previous day |
| 6:00 PM | 11:30 PM | previous day |
| 9:00 PM | 2:30 AM | same day |
Why people convert ACST to AKST time
- Scheduling a call from ACST to AKST: a 10:00 AM start in ACST lands at 3:30 PM in AKST the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -18h 30m gap: ACST and AKST 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 AKST is 2:30 PM in ACST.
- Keeping family and friends in sync: knowing that 8:00 PM in ACST is 1:30 AM in AKST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM ACST" is unambiguous; "3 PM" across a -18h 30m gap is not.
- With a -18h 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 AKST 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 AKST (Alaska Standard Time)
Alaska Standard Time (AKST) is used in nearly all of Alaska. Due to Alaska's vast geographic size, the Aleutian Islands use Hawaii-Aleutian Standard Time instead. During summer months, Alaska switches to Alaska Daylight Time (AKDT, UTC-08:00).
Best time to call between ACST and AKST
With a -18h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. AKST opens at 9:00 AM AKST, which is 2:30 PM in ACST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
ACST and AKST have no shared working hours because of the -18h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.
ACST is 18 hours 30 minutes behind AKST (ACST UTC+09:30 → AKST UTC-09:00). 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
AKST
☀ Currently in DST
Standard: UTC-09:00 · DST: UTC-08:00
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 AKST?
ACST (ACST, UTC+09:30) is 18 hours 30 minutes behind AKST (AKST, UTC-09:00). The gap is currently -18h 30m.
How do I convert ACST time to AKST time?
Add -18h 30m to ACST local time. For example, 9:00 AM in ACST is 2:30 PM in AKST (previous day).
What time is it in AKST right now?
AKST uses AKST at UTC-09:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -18h 30m offset from ACST.
What is the best time to call AKST from ACST?
There is no shared working-hours window because of the -18h 30m gap. The closest option is 1:00 PM in ACST, which is 6:30 PM in AKST.
Which is behind, ACST or AKST?
ACST is 18 hours 30 minutes behind AKST. When it is 12:00 PM in ACST it is 5:30 PM in AKST.
Does daylight saving time affect the ACST–AKST difference?
Neither zone observes daylight saving time, so the -18h 30m offset between ACST and AKST 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 AKST?
Sometimes. The -18h 30m gap is large enough that 8:00 PM or later in ACST already falls on the in AKST.
What is the time difference between ACST and AKST?
AKST is -18h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is AKST in?
AKST 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 AKST timezone?
Major cities in the AKST timezone include Anchorage, Fairbanks, Juneau, Sitka, Wasilla.
What is the UTC offset for AKST?
Alaska Standard Time (AKST) is at UTC-09:00. During daylight saving time, it shifts to AKDT.
What should I know about the AKST timezone?
Alaska is the largest US state by area but has only about 730,000 residents. Anchorage is the most populous city in AKST with about 290,000 people.
When is it midnight in ACST, what time is it in AKST?
When it is 12:00 AM (midnight) in ACST (ACST), it is -18h 30m later in AKST (AKST).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More ACST time conversions
- acst to new york
- acst to london
- acst to dubai
- acst to tokyo
- acst to singapore
- acst to sydney
- acst to los angeles
- acst to paris
- acst to delhi
- acst to mumbai
- acst to berlin
- acst to hong kong
- acst to toronto
- acst to kathmandu
- new york to acst
- london to acst
- dubai to acst
- tokyo to acst
- singapore to acst
- sydney to acst
- los angeles to acst
- paris to acst
- delhi to acst
- mumbai to acst
- berlin to acst
- hong kong to acst
- toronto to acst
- kathmandu to acst
See every conversion from ACST →·See every conversion from AKST →