ACDT to HST Converter
This page converts Australian Central Daylight Time (ACDT) to Hawaii Standard Time (HST). HST is 20 hours and 30 minutes behind ACDT, so a meeting at one time slides predictably to the other. Edit the time or date to begin.
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 Daylight Time (ACDT).
ACDT to HST conversion chart
For example, a 9:00 AM ACDT meeting takes place at 12:30 PM HST (−1 day). Concretely, when Adelaide (ACDT) and Honolulu (HST) set up a call, hST is 20 hours and 30 minutes behind ACDT.
| ACDT time | HST time |
|---|---|
| 12:00 AM | 3:30 AM−1 day |
| 1:00 AM | 4:30 AM−1 day |
| 2:00 AM | 5:30 AM−1 day |
| 3:00 AM | 6:30 AM−1 day |
| 4:00 AM | 7:30 AM−1 day |
| 5:00 AM | 8:30 AM−1 day |
| 6:00 AM | 9:30 AM−1 day |
| 7:00 AM | 10:30 AM−1 day |
| 8:00 AM | 11:30 AM−1 day |
| 9:00 AM | 12:30 PM−1 day |
| 10:00 AM | 1:30 PM−1 day |
| 11:00 AM | 2:30 PM−1 day |
| 12:00 PM | 3:30 PM−1 day |
| 1:00 PM | 4:30 PM−1 day |
| 2:00 PM | 5:30 PM−1 day |
| 3:00 PM | 6:30 PM−1 day |
| 4:00 PM | 7:30 PM−1 day |
| 5:00 PM | 8:30 PM−1 day |
| 6:00 PM | 9:30 PM−1 day |
| 7:00 PM | 10:30 PM−1 day |
| 8:00 PM | 11:30 PM−1 day |
| 9:00 PM | 12:30 AM |
| 10:00 PM | 1:30 AM |
| 11:00 PM | 2:30 AM |
This chart uses the fixed ACDT and HST offsets; the live converter above follows current daylight saving.
Convert ACDT to HST Time Zone
Everything you need for ACDT to HST — the difference, the current times, and how to plan around it.
Converting ACDT to HST, step by step
It takes three quick steps:
- Click the ACDT 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 ACDT and HST?
HST is 20 hours and 30 minutes behind ACDT. In everyday terms, once you know the time on one side you just subtract 20 hours 30 min to get the other — so a call between Adelaide and Honolulu is always 20 hours 30 min apart.
What time is it in HST right now?
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.
What time is it in ACDT right now?
And in Australian Central Daylight Time (ACDT), it’s currently Tuesday, June 30, 2026 · 4:24:05 AM. Compare the two and the 20 hours 30 min gap is easy to see.
What's the best time for a ACDT–HST call?
For example, a 9:00 AM ACDT meeting takes place at 12:30 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.
How does daylight saving affect ACDT to HST?
The labels ACDT 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.
Why can you trust this ACDT to HST converter?
Every conversion here is calculated from the IANA time zone database — the same source your phone, computer, and browser rely on. Plenty of tools hard-code a single offset, which quietly goes wrong whenever a region changes its rules or flips for daylight saving. We follow the real rules instead, so ACDT to HST stays accurate for today and for any past or future date you type in.
Convert ACDT 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
- ACST Australian Central Standard 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 ACDT is HST?
HST is 20 hours and 30 minutes behind ACDT — a fixed 20 hours and 30 minutes difference, since both are fixed-offset labels.
What time is it in HST when it's 12:00 PM ACDT?
When it's 12:00 PM (noon) ACDT, it's 3:30 PM HST the previous day.
Do ACDT or HST use daylight saving time?
Australian Central Daylight Time (ACDT) observes daylight saving, alternating with ACST; Hawaii Standard Time (HST) is a fixed offset with no daylight saving.
Why might the real-world ACDT–HST difference change during the year?
The labels ACDT and HST are fixed offsets, so this converter is always exact. But Australian Central Daylight Time's region switches between standard and summer time, so for part of the year you may actually want ACST to HST. Always check which label a region is currently using before you schedule.