ACST to HST Converter
HST is 19 hours and 30 minutes behind ACST. This converter turns any Australian Central Standard Time (ACST) time into Hawaii Standard Time (HST) — just click the time or date to change it.
Daylight saving notes
In southern Australia, daylight saving time runs from the first Sunday in October to the first Sunday in April. That affects Australian Central Standard Time (ACST).
ACST to HST conversion chart
For example, a 9:00 AM ACST meeting takes place at 1:30 PM HST (−1 day). Concretely, when Adelaide (ACST) and Honolulu (HST) set up a call, hST is 19 hours and 30 minutes behind ACST.
| ACST time | HST time |
|---|---|
| 12:00 AM | 4:30 AM−1 day |
| 1:00 AM | 5:30 AM−1 day |
| 2:00 AM | 6:30 AM−1 day |
| 3:00 AM | 7:30 AM−1 day |
| 4:00 AM | 8:30 AM−1 day |
| 5:00 AM | 9:30 AM−1 day |
| 6:00 AM | 10:30 AM−1 day |
| 7:00 AM | 11:30 AM−1 day |
| 8:00 AM | 12:30 PM−1 day |
| 9:00 AM | 1:30 PM−1 day |
| 10:00 AM | 2:30 PM−1 day |
| 11:00 AM | 3:30 PM−1 day |
| 12:00 PM | 4:30 PM−1 day |
| 1:00 PM | 5:30 PM−1 day |
| 2:00 PM | 6:30 PM−1 day |
| 3:00 PM | 7:30 PM−1 day |
| 4:00 PM | 8:30 PM−1 day |
| 5:00 PM | 9:30 PM−1 day |
| 6:00 PM | 10:30 PM−1 day |
| 7:00 PM | 11:30 PM−1 day |
| 8:00 PM | 12:30 AM |
| 9:00 PM | 1:30 AM |
| 10:00 PM | 2:30 AM |
| 11:00 PM | 3:30 AM |
This chart uses the fixed ACST and HST offsets; the live converter above follows current daylight saving.
Convert ACST to HST Time Zone
Everything you need for ACST to HST — the difference, the current times, and how to plan around it.
How does the ACST to HST converter work?
It takes three quick steps:
- Click the ACST field on the left and pick the time you want to convert.
- The matching HST time updates on the right automatically — there’s no button to press.
- Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.
What is the time difference between ACST and HST?
HST is 19 hours and 30 minutes behind ACST. In everyday terms, once you know the time on one side you just subtract 19 hours 30 min to get the other — so a call between Adelaide and Honolulu is always 19 hours 30 min apart.
What's the current time in HST?
Right now the time in Hawaii Standard Time (HST) is Monday, June 29, 2026 · 7:54:05 AM. It ticks every second, so you’re always looking at the live HST clock.
And what time is it in ACST?
And in Australian Central Standard Time (ACST), it’s currently Tuesday, June 30, 2026 · 3:24:05 AM. Compare the two and the 19 hours 30 min gap is easy to see.
Planning a meeting across ACST and HST?
For example, a 9:00 AM ACST meeting takes place at 1:30 PM HST (−1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.
Does daylight saving time change the ACST–HST difference?
The labels ACST and HST are fixed offsets, so the result on this page is always exact. One side switches between standard and summer time while the other stays put, so the real-world gap can shift by an hour for part of the year. It's worth checking which label a region is actually using before you lock in a time.
How accurate is this ACST to HST conversion?
We don’t guess. ACST and HST times are worked out from the official IANA time zone database, the trusted standard that operating systems use worldwide. Because daylight-saving rules and regional offsets do change over time, we track those updates rather than relying on a fixed number — which is exactly where many converters slip up.
Convert ACST to other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Convert to HST from other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Frequently asked questions
How many hours behind ACST is HST?
HST is 19 hours and 30 minutes behind ACST — a fixed 19 hours and 30 minutes difference, since both are fixed-offset labels.
What time is it in HST when it's 12:00 PM ACST?
When it's 12:00 PM (noon) ACST, it's 4:30 PM HST the previous day.
Do ACST or HST use daylight saving time?
Australian Central Standard Time (ACST) observes daylight saving, alternating with ACDT; Hawaii Standard Time (HST) is a fixed offset with no daylight saving.
Why might the real-world ACST–HST difference change during the year?
The labels ACST and HST are fixed offsets, so this converter is always exact. But Australian Central Standard Time's region switches between standard and summer time, so for part of the year you may actually want ACDT to HST. Always check which label a region is currently using before you schedule.